You need to format user data, system, and cache. Then you have to flash stock recovery, the 2.0 system, and the boot image. It will take a few minutes to boot up (about 12 minutes for me). I flashed TWRP later to get it to stick. Just a note, if I unpair the watch through anything other than a TWRP wipe when it's installed, it will only boot into recovery, not the system. Then I have to format and flash everything all over again. Good luck to you.