Root:
1. Tick "Enable OEM Unlock" option in "Developer Options"
2. Turn off the phone
3. Boot Recovery by holding Vol+ and Power buttons
4. Reboot Bootloader
5. Open cmd inside adb folder and type "fastboot oem unlock" it will wipe Your phone
6. Type "fastboot reboot"
7. Wait until phone wipes data (it's very important because without it TWRP can't access data partition) and then repeat 3 and 4 steps
8. Copy recovery.img inside adb folder
9. Type "fastboot flash recovery recovery.img"
10. Type "fastboot reboot"
11. Boot TWRP
12. Use OTG cable to connect mouse to phone - because of recovery bug touch is not working in recovery mode
13. Copy SuperSu to phone or SDCard - use only patched version from this thread because other versions not working
14. Flash SuperSu (if You skip steps 12-14 and boot system, phone will overwrite TWRP with stock recovery and then You have to flash TWRP again)
15. Reboot system