Even though I knew what I was doing, I was on a new computer so I "followed" your instructions because I've never seen anyone write it out so thoroughly from no ADB at all, and glad to say you pretty much nailed it through that. Except step 2, it's more like a whole bunch of times. Don't know why you've gone un-thanked and un-replied!
Step 5 is unnecessary because of the method of setting up ADB with the path variable described in 1b (if you don't do step 1b, then the files need to be in the platform-tools folder). You just need to get to the same folder in the command prompt as the files. The command prompt by default opens to C:\Users\pyroguysf (or whatever your own name is), which is where your downloads folder is located by default, so if you unzip the files to your downloads folder, type "cd Downloads" to navigate into your downloads folder. Once you're in the same folder as the img files you unzipped, then run the commands listed in step 6, each line, one at a time. After each one, it should show the progress, and make sure it says completed not failed (I forget the exact words used) before going to the next. If it fails that's a separate topic, but it shouldn't. I always advise a factory reset after any significant software changes. Re-locking the bootloader is for security's sake, and while not 100% necessary, is highly recommended, unless you plan to be changing the software again anytime soon (I see a modified version in this thread that supposedly has OTA's disabled I might try, but this is slightly more advanced). Re-locking is basically the reverse of step 3 - reboot into bootloader with "adb reboot bootloader" and then once it's there "fastboot oem lock" instead of unlock.
Edit: That's right, you get the message upon boot for a while that your device can't be checked for corruption when it's unlocked. Also, my watch won't boot now, so I'm going to try a few more things... That's why I waited until the weekend.
Edit2: Re-unzipped the files (md5 was fine), did boot, recovery, then system, and did "fastboot format
userdata" instead of "fastboot erase
userdata" in step 6.
Edit3: Edited the quote from MK2ever below with what worked for me.
Originally Posted by MK24ever
Ok, I've been doing some reading and I'm almost ready to flash the watch back to 1.5, but just in case I'll make here the full list of what I've done/about to do, please check if all is correct:
1 - Download and place the Platform-tools folder from here on a easy access place to access on your PC
1.b - Edit Path Variable as shown here just be make things easier
2 - Enable USB debugging on watch by going to the watch Settings/System/About and pressing repeatedly on the Build Number until it says "you are a developer!"
2A. Go to Settings>Developer Options and turn on "ADB Debugging" and plug your watch cradle into your computer and wait until windows installs drivers (Win 7 found them automatically for me)
2.B - To check if the connection is well done between watch and PC open a command line on Windows and write "adb devices", it should show the watch SN listed
2.C - when your watch asks to allow connections, tap "always allow from this computer"
3 - Unlock the bootloader!
3.1 - Reboot to fastboot (via *adb command* (You do this by opening a command prompt window from within windows itself) "adb reboot bootloader")
3.2 - wait until the watch says "fastboot mode" then type command "fastboot oem unlock"
4 - Download STOCK ROM MWG68 images
5 - Place the unzipped files system.img boot.img and recovery.img into your downloads folder.
6 - Open a command prompt window and type "cd Downloads" to get to navigate into your downloads folder (Windows 7 default, 8 and 10 too I think) and then enter the following commands one at a time waiting for it to give a "completed" message before moving on
fastboot flash boot boot.img
fastboot flash recovery recovery.img
fastboot flash system system.img
fastboot format userdata
7 - make factory reset on watch by... "unpair and reset" in the watch settings...
7.1 - Re-lock bootloader is advised. Repeat steps 2 through 3.1 and then "fastboot oem lock"
8 - Don't install AW 2.0 again?