My method is to pull off the eeeprom info via a game save hack and put it in the appropriate xboxhdm folder. I have one folder for each different kernel. From here I create and burn the iso, build the upgraded drive, take it apart, put it in, transfer saves, and voila, your very own media center.
Note: Each xboxhdm folder is already made up with UXE in place. You can build one folder and simply duplicate it with the same dash in place, just change the font files so they correspond to the kernel.
I know there is a better, somewhat Live friendly method now but I have not experimented with this as I use Kai. It's definitely reliable and safe as you don't alter the stock drive and you're forced to back up the eeprom info. I haven't had one box returned yet and I've done a good number.