I happen to buy a couple xboxs cheap and would like to softmod them to play backups.
I have another xbox with a mod chip. What is the easiest way to mod the ones I just bought. I am wondering if it is easier if I can use the one with the mod chip to do the hard drive on the new ones?

What you are suggesting isn't possible.

Gamesave softmod is the easiest way. Get an Xbox memory card, or a USB stick and an Xbox-USB adapter, and an exploitable game. Get hold of the Krayzie 1.1.1 gamesave softmod. FTP the gamesave to your chipped Xbox, copy it to the MU, transfer it to the unmodded Xbox. Run the game, load the gamesave, follow the instructions.

I do not have an exploitable game. Is there a way to install the modchip in the new xboxs ttemperarly just to hack it so it will play backups , remove the modchip and still have it play backups
thanks

Yes. You'll need a solderless adapter to temporarily install the modchip into one of the other Xboxes. Once it's installed you can ftp a Kingroach NDURE 3.1 softmod onto the Xbox, then remove the chip. The Xboxes will have to be able to run the same BIOS i.e. all 1.5 or below, or all 1.6, or you'll need a chip with two banks so you can switch between two BIOSes.