Prerequisites
- HTC Android USB drivers properly configured and installed.
- USB Debugging enabled on your HTC One M8.
- A complete backup of all your data on your M8.
- A fully charged device.
With the formalities out of the way, let’s get started.
Step 1: First and foremost, you’ll need to gain S-OFF using the firewater S-OFF software located at: firewater-soff.com
Step 2: Now, head over to SIEEMPI (here), enter the required details including IMEI and email, and once you have done so, you’ll be mailed a unique file specific to your particular device. Download it.
Step 3: Place the downloaded config.dat file into your microSD card’s /root folder.
Step 4: Press and hold Power + Volume Down to boot in bootloader mode.
Step 5: Using your volume toggle, scroll to the SIMLock feature, then press the Power button.
Step 6: Once the config.dat file downloaded in Step 2/3 has been applied, simply follow the on-screen steps, and after a short wait, your device should be SIM unlocked.
Once you’ve followed the guide, check that the magic has happened by placing another SIM into your handset.