There are several different kinds of disc drives that come in different iterations of the XBox 360, and each one has to be hacked a little differently. This video will show you how to flash the ms28 drive used in some systems, the second part of the video will show you how to determine what model of drive you have. It is very detailed, and should have you well on your way to hacking you beloved XBox 360 and maximizing its potential.
Stuff you'll need, from the creator:
-VIA VT6421A SATA card
These software programs:
Microsoft .NET Framework v2 (make sure you have this installed)
/XBOX 360/firmware/hacked firmware/Toshiba-Samsung TS-H943/
/XBOX 360/firmware/firmware tools/iPrep 101/
Simply drag the Samsung.iXtreme.1.5.rar & iPrep008.8.rar file to the left, or right click and select download.