[Verizon Droid Incredible 2] 121tech:
Enabling GSM

Easy enough.

OPTION 1: Use the VZW/Vodafone GSM SIM already installed in your phone. You are free to roam the world. Oh, and have your Financial Advisor transfer ready funds to an account and tell VZW they're going to have a great quarter.

OPTION 2: You need to have your phone SIM Unlocked so you can insert a SIM Card from another service provider. If you are a current VZW customer in good standing you can call VZW CS and ask them for the SIM Unlock Code. Or go to one of the shady websites and buy a SIM Unlock Code. Once SIM Unlocked,

1. Buy a 'Pre-Paid' SIM Card for the country you're visiting. Make sure their GSM network operates on the same frequencies as your phone, GSM: 850 / 900 / 1800 / 1900 HSDPA: 900 / 2100

2. Open the back, pull the battery, depress the 'catch' locking the SIM Card in place and ease the current SIM Card down and out. Insert the new SIM Card (remember, cut corner bottom right). Replace the battery and cover.

3. Power on the phone. Once booted, open the dialer app and dial * # * # 4 6 3 6 # * # * and wait for the "Testing" menu to appear

-- select --> "Phone Information"

At the VERY BOTTOM of the text list you'll find "Set preferred network type"

-- select --> "WCDMA preferred" in pull-down list ; (or, optionally, "GSM only" or "WCDMA only")

note: when I used Polymath257's compiled AOSP 4.4.2 KitKat rom it sometimes showed "Unknown" in the "Set preferred network" pull-down menu field and the radio status toggle button right below it showed "Turn on radio" (meaning the radio was currently disabled). Pressing the "Turn on radio" button and waiting for the radio to initialize then allows a "Set preferred network type" selection to actually stick.

-- Press HOME. REBOOT the phone.

The signal icon should now show bars in the status bar.

note: When Powering-On or Rebooting the phone, you may need to 'toggle' "Airplane Mode" to regain GSM radio service. No need to revisit the Testing menu until you want to switch back to VZW CDMA service via -- select --> CDMA auto (PRL).

If you want to use MMS and/or Mobile Data (2G/EDGE, 3G/HSPA etc) you will also need to create "Access Point Names" that work with your SIM Card network operator.

-- Menu | System Settings | Wireless & Networks (More...) | Mobile Networks

Set each of the following for your preferences:

-- Data enabled (check box ON or OFF)

-- Preferred network type (3G or 2G)

-- Access Point Names (enter info provided by your network operator for Internet and MMS)

-- Network Operators ( --select--> Choose automatically )

note: Be very careful with the 'Data enabled' toggle. Many GSM mobile data contracts are set to bill 'per minute' or 'per kilobyte' or 'per megabyte' after you have exhausted your selected data plan, meaning overages will use up your prepaid balance very quickly. Setting Android Play Store Updates to manual, turning off 'Data enable' and using WiFi when available can help.

Also I'd suggest downloading Network Signal / Network Signal Pro from the Play Store, it gives great information on your phones active cell, data and wifi connections.

PS: I wrote this using Chily's 4.4.2 KitKat Beanstalk rom, most of the settings 'should' be the same.