Here are the steps I did a few days ago...
First... make sure you have Moto drivers 5.4.0 (or newer) installed on your PC. Install RadioComm (I used 11.12.2). The first time you do this and use Radiocomm, you will be prompted for other drivers to install, let them.
- Boot Bionic, connect USB cable, put in PC MODE
- Start RadioComm
- select Main -> MA -> Common -> MDM 6x00 chipset base
- select settings -> USB -> USB PST Driver
- select the FTM Common1 tab
- Try the buttons at top to read Version and MEID, if response is GREEN, you can proceed. If RED, there is likely a driver error that you need to resolve. (If drivers are correct, you should see moto usb networking listed under NETWORK Adapters in Windows Device Manager). Possible ways to fix driver issue... 1. re-install Moto 5.4.0 drivers and reboot PC. 2. reboot phone (remove/replace battery if possible). 3. when connecting phone to PC, ensure its connected in PC MODE, not USB Mass Storage, Charge Only or other...
- in the NVAccess drop down, select 1877
- click read.
- should show 07000000000000000.... change the first characters to... 8703E80400000200
- click write
- exit radiocomm
- disconnect phone
- power phone off, insert Non-VZW SIM, and power up.
As the phone boots, you should see no signal, then white signal indicator which should eventually show E (for edge) on T-Mo, or 3G or H+ on ATT. You'll get errors about gmail account authentication, after you re-enter your gmail passwords, then signal indicator should go BLUE.
It may take a while to get signal. For ATT I never got anything but 3G. With that same ATT SIM in a HTC Galaxy Note, we did have H+ coverage.
If you want to use on Verizon again, just shut down, put in the VZW SIM, and power up. Again, you'll have to re-enter your gmail account passwords.