1. The only real reason to unroot is if you need to send the phone in for warranty or if you want to just start from scratch.
1. Download RSD Lite, the 2.2 .sbf file, and the Motorola Drivers.
2. Install RSDLite by double clicking the RSD Lite.msi file you just downloaded.
3. Once RSDLite is installed, unzip the drivers folder you downloaded (32 bit OR 64 bit), then double click the Motorola Consumer Driver Installer application and install the drivers.
4. Plug in your phone to the computer via USB cable.
5. Turn the phone off while it is plugged in.
6. Turn on the phone by holding down Power and UP on the DPad of the keyboard on the phone for 5 seconds then let go.
7. Open the RSDLite program by right clicking it and selecting Run As Administrator.
8. Click on the “…” button next to the filename box and select the .sbf file you downloaded earlier.
9. Once it is selected, hit Start and wait for it to finish flashing the phone.
10. Once it is done, the phone should reboot and you are now on Android 2.2 stock and are all set.