OK, here we go for the Samsung laser replacement, you can see how to do the Hitachi drive HERE
First take the 360 apart and remove the DVD drive. If ya can't find this sort of tutorial on yer own or haven't already gotten this far then ya should stop now and go look that up first, then come back and read thru this a few times before trying it. Replacing the laser isn't a huge or complex deal and requires minimum tools (couple of Phillips head screwdrivers, #1 and #0 and a Soldering Iron) but it's still something that needs to be done correctly and has it's risks.
First remove the 4 screws on the bottom of the drive, these hold the case together. Once you have them out, remove the bottom cover and then pull the top cover off.
Once ya have the case apart you need to unplug the flex cable that goes to the Laser first. Be careful and make sure you have a firm even grip on the cable with your thumb and index finger and keep the laser in place with your other hand as it will want to move back when you pull on the cable if not held in place. Then pull it straight out, in a motion towards the back of the DVD drive, NOT upwards or any other direction, towards the back of the DVD drive.
Once you have that removed, flip the drive over and unplug ONLY the Spindle motor and Tray motor cables, just pull them straight out same as the Laser's cable. We'll get to the Sled motor cable in a second. Pay attention to where the Clip and Notch areas are as they are going to be used here in a second.
Now be very careful with this part so you don't ruin the flex cable that goes to the Sled Motor. There is a plastic clip that needs to be pushed to the side just a little bit so this side of the Logic board will lift free. Push it over and pull the board up just enough to clear the clip...
...then by sliding the board over just a little bit, make sure the tab on the Logic board if out of the Notch...
After the tab on the board is free from the Notch, gently lift the board like you're opening a book with the side the Sled Motor Cable is on acting as the spine, or hinge if you prefer. Do NOT let it use the cable as a hinge or put any unnecessary stress on the cable, lift the board up just enough so you can get to it and unplug it.
Once ya have the Logic board free, set it out of the way for now someplace safe. Now, before proceeding any further manually eject the tray. Since you have it all apart it's easiest to do from inside the drive, just use a small screwdriver or your finger and push the sled elevator over, this will lower the sled and eject the tray pretty much at the same time. It doesn't eject the tray all the way, just far enough to grab the tray and then you can just pull it the rest of the way open.
Once you have the tray open you need to mark the location of these spots. They adjust the tilt/angle of the Sled and thus how the Laser hits the disc. If either were to become out of adjustment you'll have problems reading some discs. There is an arrow on each one and you can just use a Sharpie or other marker to indicate which way they were originally facing. (NOTE: They may already be marked,but mark them again so you know exactly which way they need to face when you're done) You should do this because one of these is more than likely going to get turned a little removing the rail here in a few seconds, and just in case they get moved anyway you'll know where they were to start with and should be.
After marking the tilt/angle spots, close the tray by giving it a push until it's all the way in. Now there is 1 screw and Cap that you need to remove the get the drive rail free before the Laser assembly will come out.
Once removed, set it off to the side someplace safe as well. NOTE: It has 3 small tabs on it, so while you can reinstall it the wrong way (with force) it's designed so ya don't, as long as you're paying attention. There are 3 small notches on the other part that this one sits in, so you shouldn't have any issues putting it back in there later.
Once the Cap is removed lift the rail up slightly at the end where the Cap was, and pull towards the back of the DVD drive, and out the entire laser assembly should come. BE CAREFUL of the spring on the white part there, it's to keep tension on the Sled motor's worm gear so it can move the Laser back and forth, just don't let the spring go flying away from ya. If it comes out it's easily put back in place, provided ya didn't loose it.
Now you need to prepare your new laser before installing it. Be careful as to not touch the lens as by now you have grease on your hands form taking the drive apart and touching the rails and such. If the Laser is from another working drive you don't have to do this as it's already been removed, but if you have a brand new Laser this will need to be done or it will not work. Get out the soldering iron and warm it up, then remove this solder bridge here so the points are cleared. Use solder wick if you wish, but just a pass or 2 over the spot is usually enough to clear the contacts of the solder. Just make sure you have it all off of there and do NOT go leaving the Soldering Iron on there for too long, this should only take a second or two at most.
ANTI-STATIC POINT (New Laser)
ANTI-STATIC POINT REMOVED (Read for Install)
Once you have the new Laser's anti-static point removed you need to take the old Laser and remove the Tensioner (that white part with the spring) and the drive rail and install them on the new Laser. The drive rail just slides right out and you can place it in the new Laser in either direction, it'll work either way. Then remove the Tensioner, there is 1 screw that holds it onto the Laser, and install it on the new one.
Once you have that all done the new Laser is ready to be installed. You can see better how this actually goes when doing it, but it's a pretty simple 3 step process to get the thing reinstalled properly that all sorta flows together in one step once ya know what you're doing.
STEP 1. Place the notched side of the Laser on the metal rail there.
STEP 2. Put the other metal rail into the notch where it was originally.
STEP. 3 Set the other end of the metal rail back into it's spot and then reinstall the Cap and screw you removed that held it in place.
Once you have that done gently push the Laser assembly toward the center of the drive so you'll have room to reinstall the flex cable in a little bit.
The rest of the "put it back together" is the opposite of the tear down. Take the Logic board and plug back up the Sled motor cable, careful to not get the end of the cable sideways or at some weird angle when plugging it back into the connector as it can be messed up easily. Reinstall the Logic board, remember the Notch and place the tab on the Logic board in there, then just push the other side down and the clip you moved earlier to release the board will catch and hold it in place.
Plug up the Spindle motor and Tray motor cables, taking care with them as well. You may find this a little difficult as the connectors are on the opposite side of the board, so one thing you can do is plug them up BEFORE you plug in the Sled motor cable. This makes getting the Sled motor cable plugged in a little more difficult, so ya just have to pick the lesser of the two evils and do whichever works easiest for you.
Flip the drive back over and plug up the cable to the new Laser. Be very careful with this as well since it has quite a few connections on it and you don't want to mess any up at all. Just get it lined up straight and apply even pressure to reinsert it, you want it to go in square and not at an off angle either or you may cause damage to it.
Once ya have all that done manually eject the tray again and make sure the adjustments for the tilt/angle of the Sled are where they should be, turn them to where your marks were if they were moved. Then just close the tray again, reinstall the case top and bottom, then put the screws back in and there ya go.