Had to use the same process for IPrep flash as I used for xtreme flash, which was given by bigd23. All is well and running strong. Below is the information given by bigd23.
Do you have a valid orig.bin in the \BACKUPS\xxxxxxx\yyyyy folder on your USB drive? If so boot into Windows and create a new folder on C: and copy your orig.bin + samtool.exe + the hacked 5.2 firmware from the root of the USB drive to that folder. Then open a command prompt in Windows, switch to the folder you created, and run...
samtool <original firmware> <hacked firmware>
For example...
samtool orig.bin xtremefw.bin
Samtool will run and you should see a green success message about the keys matching. Then copy the hacked firmware you just created to the \BACKUPS\xxxxxxx\yyyyy folder on your USB drive, boot into DOS and proceed with the flashing step.
