Rooting the SmartWatch 3 cost me way to much time through trial and error, so here is a little tutorial for you guys:
- Download and extract this: https://drive.google.com/open?id=0BzOF0XGjhOopWHozY0NnV2E1Z2c
- Enable ADB-Debugging on you watch and plug your USB cable in.
- On your PC make sure you have adb & fastboot installed and type in adb reboot bootloader
- Make sure your bootloader is unlocked! (fastboot oem unlock)
- There is no stable TWRP recovery (yet?) for firstname.lastname@example.org, so make sure you only boot and do not flash the following image via fastboot boot new_boot.img
- After a few seconds you should be in TWRP now, if not try booting again, if nothing works, repair your firmware with the Sony Xperia Companion app (restoring android wear only works in their PC version)
- Push a modified supersu to your watch by using adb push wearSU267.zip /sdcard
- Install the zip via TWRP and follow the process, reboot.
- You have SU!