From this link:
Droid X
Windows Instructions:
1. Download RSD Lite (credit to MyDroidWorld)
2. Install the RSDLite 4.7 program by double clicking on the program.
3. Move the pst_flash.ini file into the following folder --> Program Files/Motorola/RSDLite
4. Install the drivers that apply to your Operating System.
5. Unzip the SBF into a folder. (Download Above)
6. Open RSD Lite and find the UNZIPPED SBF
7. Put your Motorola Droid X into bootloader. (turn phone off and hold volume down and the camera button while pressing the power button)
8. Click start and sit back.
Note: after the flash will need to boot into recovery (hold volume down and the home button) and wipe data and cache.
Thanks so much for the help!!