I. Before You Begin1. This will work on all models of the HTC One M8 (AT&T, T-Mobile, Sprint, and International Models). Apparently, Verizon has blocked their devices from being able to use HTC’s bootloader unlocking tool, so theyare stuck for now unfortunately.2. Make sure your battery is over 75% charged to ensure it doesn’t die unexpectedly during this process.3. This process may void all or parts of your warranty according to HTC.4. This will erase all the information on your device, so be sure to save anything you wantto keep to your computer before continuing.5. This only works for PCs.6. On the HTC One M8, go to Settings > Battery Manager > Turn OFF Fastboot.II. Download and Install the Toolkit1. Head to the developer’s pagehereand download the latest version of the toolkit yousee on that page and save it to your desktop.2. DownloadWinRarand install that so you can extract his toolkit if you don’t have a wayto extract .rar files already.3. After installing WinRar, right-click the toolkit .rar file you downloaded earlier and select extract all.III. Unlock Your HTC One M8’s Bootloader1. Open the toolkit.2. Select Download HTC Drivers and click Go.3. Install the drivers.4. Back in the toolkit, select Register at HTCDev and hit go (follow the steps on the HTCDev site to register or login if you alreadyhave an account).5. On the HTC One M8, go to Settings > About > Software Information > Tap build number over and over until it tells you you are now a developer.6. Go to Settings > Developer Options and turn ON USB Debugging.7. Plug the HTC One M8 in via USB.8. Highlight Get Token ID and click Go.9. Close the command prompt when the device enters Fastboot mode.10. Right-click in the second command prompt and select Mark and copy everything from <<<< Identifier Token Start >>>> to <<<<< Identifier Token End >>>>> and paste itinto a text editor for later use.11. Highlight Submit Token ID and hit Go.12. Login to HTCDev and then go to HTCDev.com and click on Unlock Bootloader.13. Select the HTC One M8 from the drop down on the right and click Begin Unlock Bootloader.14. Skip the steps and hit next until you get to a text box to input the Token ID.15. Paste your entire Token ID into the text box and click Submit.16. Save the Unlock_code.bin file that is emailed to you to your desktop.17. Highlight Unlock Bootloader and click Go.18. Select the Unlock_code.bin file and click OK.19. On the device, use the volume button to highlight Yes and push power to select it.20. Go through your setup process when it reboots.III. Flash a Custom Recovery on theHTC One M81. Reenable USB Debugging by going to Settings > About > Software Information > Tap build number over and over until it tells you you are now a developer.2. Go to Settings > Developer Options and turn ON USB Debugging.3. Highlight the custom recovery you want toflash (the ones labelled for specific carriers i.e. Sprint must be used if using that version of the device) and click Flash Recovery.4. When the device boots back into Fastboot mode, close the first command prompt.5. When it says finished in the second command prompt, close it.6. Using the volume buttons to navigate and power to select choose Reboot on the device.IV. Root the HTC One M81. Highlight Perm Room under Extras and click Run.2. After you see that a file transferred, close the first command prompt.3. Once the device reboots into recovery mode, tap on Install.4. Select the SuperSU.zip file and swipe to flash it.5. Tap Reboot > System.6. All done!V. Gain S-Off on the HTC One M8 (Optional)1. Now that you have root and a recovery image, the next thing to do is to gain S-Off soyou have total access for flashing fancy ROMs and tweaks (like the Harman/Kardon audio enhancements). Head to myHow To Gain S-Off on the HTC One M8 videoto do that.