You can start by going
here and gething your Sprint OEM ROM.
From there you wanna do a hard reset first by pressing both 'minus' keys on the from of the device and pressing and holding the reset button in the bottom of the device for a few secs. This is prompt you to press "Y" on the keyboard to comfirm what you are doing.
This reset everything back to factory settings and clears all personal settings.
If you havent gotten ActiveSync yet then go
here and DL it.
After installing it, take the PPC and press and hold both the power button and the record button at the same time and continue to hold them while pressing the reset bottom with the stylus on the bottom of the device. This is put you in a BootLoaded mode. The backlight will not be on and you will see Serial at the bottom of the screen. If you connect the PPC via USB to the computer the screen will change a slight bit to USB. From there run the .exe of the ROM you DL'ed earlier and and follow the prompts.
Thats it. Nothing major or hard about it.