OK, I found the instructions on Droid Forums..
Pull up the dialer on your phone
Dial ##PROGRAM (##7764726)
Hit Send (the call button)
The password is 000000 (six zeros)
Select "Option 6 - Test Mode"
Hit "Next" until you come to the "Field test screen"
Under "Service Option" (top most), select EVRC-B
The phone should then reboot and you'll be all set.