I got this from a thread by mmrz. over at androidcentral. It Worked for me
Flashing a Rom - Now that you have a backup of your phone you can safely flash a custom rom. Only flash roms meant for your phone. You can flash them using adb, booting into the recovery, or using Romtools posted above.
To install using your custom recovery, place your rom zip file onto your microsd card. Boot into your recovery using the method outlined in the previous step. Use the install zip function to install the rom. Navigate to your rom zip file, and install it.
To install a rom using Romtools, follow the directions in the link posted above. Don't forget to manually make a backup first using the custom recovery. Romtools doesn't have a backup feature.