I wrote tutorial a few months back for for flashing MS25 T/S drives. Here is how to flash an MS28. It is mostly the same but a few steps differ. I will highlight them in red. The biggest difference is that the MS28 drive can only be read and flashed as the 360 is being started. The tutorial addresses this.
The easiest and safest way is to use a program called extreme boot maker. Its really quite easy.... assuming you can get the damn 360 case apart. Here is my tutorial, some of it comes from the readme. I still am not covering Hitachi drives at this time. See what drive you have here: http://www.ps3news.com/forums/x-box-...son-11787.html
Extreme Boot maker is essential to this process, with admin's permission I will upload it.
Xbox 360 with TS DVD drive
Tools to open 360 case
Sata Capable PC (or certain addon cards)
Thumb Drive or Floppy (highly unreliable and risky!) or CDR (not recommended since you can't save to it)
Extreme Boot Maker
Commodre4ever's Xtreme Firmware (in firmware forum on this site).
1. Download xtreme firmware from above. Download Exteme Bootmaker from somewhere.
2. Load your floppy disk or connect your USB Flash Drive.
3. Run Xtreme Boot Maker. See attached picture.
3a. click open, select your extreme firmware
3b. check "use custom mtkflash"
3c. select your computer's sata from the dropdown
3d. click "detect I/O"
3e. check both boke's patch and the bad flash ms28 patch.
3f. Select your thumbdrive/floppy/cd burner (with a CDR inserted) and check "make bootable".
*note* I highly reccomend not using a CDR. If you use a CDR, you cannot backup and later restore your old firmware!
3g. then click "prepare drive"
3f. There are new versions of x360sam and keycheck programs than the ones included in the bootmaker. If you plan to use 5.2, you may want to find them or you could get error E66. Once you do, put them in the folder: USB/floppy/XBF.
4. Take off the faceplate from the front of the 360. It is significantly more difficult to do than it should be. Try to position your fingers inside the memory card slots.
5. (optional) Use the hairdryer to heat the sticker for a few minutes, then carefully and slowly pull it off. With some luck, you will not void your warrenty!
6. Take your 360 apart. This is by far the hardest step and I really can't help you much. I used a combination of thumbtacks and some eyeglass screwdrivers I borrowed and the back of my 360 is mangled (which voids my warrenty even though the sticker is perfect). I have heard of some people chopping up a spindle, and there are tools available to buy online.
7. Go into your computer's bios and tell it to boot from the floppy drive, usb drive, or cdrom depending on which you used above. Usually this option is in advanced settings. Turn off the PC.
8. Disconnect all drives from your pc except the one you need to run the boot device you made. Then connect the Sata cable from your PC to right next to the 360 DVD drive. Leave the power connected to the drive from the 360.
9. Turn on your PC and Xbox 360 at the same time, and boot your PC from the floppy disk, into DOS. When you reach the DOS command prompt, plug the SATA cable into the Xbox 360 DVD drive.
10. Type "samread xxxxxxx xxxxx" to backup your 360's original firmware. The X's refer to the serial number on the back of your 360 case.
11. It should display your SATA chipset. DO NOT select the port yet. Leave it at the menu. Now, power off the Xbox 360. Select the port that the 360 drive is connected to, even though the 360 is turned off. It will pause when you select that port, giving you a port error. Count to about ten, then turn on the Xbox 360. It should start reading and dumping automatically. Be sure to wait for it to finish completely.
12. Unplug the SATA cable from the 360 DVD drive and power off the Xbox 360. Restart the computer. At the dos prompt plug in the sata cable, then type "samhack xxxxxxx xxxxx" (Don't include the quotes, and replace the X's again with your S/N).
13. It should display your SATA chipset. DO NOT select the port yet. Now, select the port that the 360 drive is connected to, even though the 360 is turned off. It will pause when you select that port, giving you a port error. Count to about ten, then turn on the Xbox 360. It should start flashing the new firmware automatically. Be sure to wait for it to finish completely.