Non-jailbroken users:
1. Plug your iPhone 5 into iTunes and backup the device so you won’t lose anything, just in case.
2. In the device itself, tap the “Settings” app and navigate to “General >Reset > Reset Network Settings”
3. Once you have done that, the iPhone will auto reboot.
4. Download the hacked carrier update here: http://www.4shared.com/file/WF0uqJL-/TMobile_US_iPhone_Hack.html
5. Now you’ll to go ahead and enable iTunes to except custom carrier bundles, if it’s not already.
6. Windows users, you will need to open command prompt and type the following and enter it in:
64 bit: cd “C:\Program Files (x86)\iTunes” then type: iTunes.exe/setPrefInt carrier-testing 1
32 bit: cd “C:\Program Files\iTunes” then type: iTunes.exe /setPrefInt carrier-testing 1
Mac users you will need to open terminal and type the following and enter it in:
Mac: defaults write com.apple.iTunes carrier-testing -bool true
7. After this has successfully been entered in restart iTunes
8. Click on the tab for your iPhone 5 and click “Update” or “Check For Update” while holding down the Alt / Option key for Mac users and the Shift key for Windows users. Navigate to where you downloaded the hacked carrier update file named “TMobile_US_iPhone.ipcc,” and select it then click Open.
9. The carrier update should now successfully be installed. Restart your iPhone 5 for any changes to take effect.
10. If you encounter any problems or wish to revert back just download the file below and repeat the above steps only with the default file instead.
STOCK CARRIER FILE HERE: Original Carrier File Link
Jailbroken Users:
1. Download the file to your device through iFile here:
2. Unarchive the files and copy the file name “overrides_N41_N42.pri” then navigate to var/mobile/Library/Carrier Bundles/TMobile_US.bundle and paste it into the folder replacing the original .pri file.
3. Reboot your device for changes to take effect.
4. If you encounter any problems or wish to revert back just download the file below and repeat the above steps only with the default file instead.