How to Root HTC M8 GSM (All Versions Supported) SuperSu 2.40 - Philz touch 6.57.8
Attention:Rooting your device may void all or parts of your warranty!!!
I-Unlock bootloader
Example:
II-After powering down, press Volume Down and while pressing Volume Down, press Power holding both buttons to start the device into Bootloader mode. If you have difficulty, power up normally, go to Settings->Battery and deselect Fast boot. Power down and try again.
III-Use the Volume buttons to select up or down. Highlight Fastboot and press the Power button.
VI-Connect your M8 to computer and Flash philz_touch_6.57.8-m8 recovery Click Here to Download or Mirror
command: fastboot flash recovery [where is your recovery file]
Example:
VII-Flash SuperSu with adbsideload command.Firstly enter recovery mode(Enter bootloader after select recovery)
Select install zip
Select install zip from sideload
VIII-install supersu2.40
Command: adb sideload [where is your supersu file]
Example:
That's All
The result