You will need a Windows PC for this. Make sure you have backed up your data before proceeding.
- Download the Samsung Android drivers for Windows from here and install it.
- Download ODIN from here and extract it.
- Download Stock ROM for flashing your T-Mobile S7 Edge device from here and extract it.
- Hold the Volume Down+Power+Home button of your device simultaneously until you see options to Flash your device.
- Now choose to move forward with flashing your device by pressing the Volume up key on your device.
- Now connect your device using a USB cable to your Windows PC.
- Run ODIN as an admin and choose the files starting with BL, AP, CP & CSC correspondingly into their respective fields and click on Start.
- Wait for the flash operation to terminate successfully. This usually takes around 5-10 minutes depending on your hardware.
Disconnect the phone from the PC and start it and configure it to restore your backup and then let it install the T-Mobile updates through multiple restarts. Now you can use your phone and still claim your warranty.
If you would like to keep the existing files then, instead of the CSC file choose the HOME_CSC file.