Have a hankering to use the HTC First, the new (possibly discontinued) Facebook phone on T-Mobile or a pre-paid carrier? AT&T is not releasing unlock codes to their customers for the HTC First until it is past its exclusive period but you can SIM unlock it on your own. Instead of paying for an unlocking service, follow the below trick to unlock the HTC First yourself, for free.
Open the terminal emulator on your phone and enter the below commands. Be sure to grant superuser user permissions in the pop-up dialog after entering the su command.
dd if=/dev/block/mmcblk0p6 of=/sdcard/mmcblk0p6
After it is done copying the partition containing the SIM unlock code to your phone’s memory, plug in your usb data cable to your HTC First and computer access internal storage. Look for the file named mmcblk0p6 and copy it to your computer.
Open mmcblk0p6 with a hex editor. Your SIM unlock code is the 8 digits starting at offset 00008939. Write this down for the next steps.
Power off your HTC First and insert another carrier’s SIM card (not AT&T.) When you power the phone back on, a screen will open where you may enter the unlock code just retrieved from mmcblk0p6. Follow the prompts to enter the unlock code.
When done, hit the “Unlock” button and the phone will power off.
When you turn your HTC First back on, it will automatically connect to your carrier’s network.
One last step:
Enter your carrier’s specific access point name (APN) information at Settings > More > Mobile Networks > Access Point Names to get mobile data and text messaging working. (Your carrier’s customer support page will have this information available.)