We have successfully converted several dozens Chinese Amazfit watches to the English Amazfit Pace firmware (see this link).
This has been tested with AmazFit Chinese FW 1.2.3 and 1.2.4b successfully.
ATTENTION: There are some people that have problems with the touchscreen after the flash. They have flashed with the watch being on a very early firmware (no updates done after purchase). Please update the watch first to a recent Chinese firmware (ideally 1.2.3 or 1.2.4b) before flashing the English version!
UPDATE: The issue has been fixed by reflashing the watches back to the old Chinese version, then updating to a current version, and finally converting the watches to English version. See here: https://forum.xda-developers.com/sma...5#post70521085
You need to have ADB and FASTBOOT installed and working on your PC. For ADB you will need the universal drivers from Khoush (if you use Windows). YOU MUST HAVE EXPERIENCE WITH ADB AND FASTBOOT!!!
I AM NOT RESPONSIBLE FOR ANY BRICKED WATCHES, LOST DATA, HEART ATTACKS OR WHATEVER. YOU DO THIS ON YOUR OWN RISK. WE CURRENTLY HAVE NO WAY TO UNBRICK A WATCH, IF SOMETHING GOES WRONG!!! YOU WILL PROBABLY ALSO VOID YOUR WARRANTY (although warranty is difficult with Chinese watches anyway). YOU HAVE BEEN WARNED!!!
OK, you want to continue? Here are the steps:
# Download the archive here: https://mega.nz/#!gQ9XiJbT!qPQD6Uw-1...k_jiOL8ezLrqvs
# unzip the archive on your PC and read the instructions
# connect your watch to your PC
# this should list your watch, otherwise something is wrong
# push the files from the archive to the watch
adb push boot.img.gz /sdcard/
adb push system.img.gz /sdcard/
adb push flash_eng_version.sh /sdcard/
adb push md5s.txt /sdcard/
# now reboot into bootloader
adb shell reboot bootloader
# when you see the fastboot logo, check that you can access fastboot
# you should see your device listed, otherwise your fastboot installation is not correct on your PC
# then boot into the temporary recovery
fastboot boot Amazfit-mod-recovery.img
# this command will end with a "FAILED" message. Don't be afraid. This is normal. It is important that you see
# a triangle and/or the text "No command" on the watch. Then you are in recovery and can enter adb.
#Check first, if adb can see the device
# if you do NOT see your watch listed, then you need to update your (Windows) adb drivers (see post #2).
# if you see your device listed, then enter adb with
# you should see only a "#", meaning you have full root access
# move to the sdcard
# you should see your files on the "sdcard", including the ones that were pushed before
# start flashing the files (THIS IS THE CRITICAL PART!!! Now, the watch gets modified! Last chance to stop. In case you changed your mind, simply type "reboot".)
# if everything worked correctly, you should see something like:
# sh flash_eng_version.sh Validating images boot.img.gz: OK system.img.gz: OK Generating backup files Creating boot.img.bak 18432+0 records in 18432+0 records out 9437184 bytes (9.0MB) copied, 3.958210 seconds, 2.3MB/s Creating system.img.bak 1687552+0 records in 1687552+0 records out 864026624 bytes (824.0MB) copied, 1821.060340 seconds, 463.3KB/s Starting to flash now. DO NOT TURN OFF OR REMOVE THE USB CABLE! THIS WOULD BRICK YOUR WATCH!! Press Enter to continue or CTRL-C to stop! Flashing boot.img 2304+0 records in 2304+0 records out 9437184 bytes (9.0MB) copied, 2.075793 seconds, 4.3MB/s Flashing system.img 210944+0 records in 210944+0 records out 864026624 bytes (824.0MB) copied, 107.981352 seconds, 7.6MB/s Finished
# If everything is ok, then you can reboot the watch
# The watch should reboot as an English version, if everything is ok. That means, first logo, then boot animation (here you are already safe!), then optimizing apps, then watch face. If your stuck at the logo, the watch might well be bricked!!!!
So far, it looks as our method completely converts the watch, as we exchange the boot and system image. You will keep your data and your serial number, though.
There are so far no long term experiences. We expect that OTAs will continue to work, but as there are so far no OTAs for the English version, we could not verify it by experiment.
I did that in my free time. I am not a professional developer, and I do not have much time (if ANY) for supporting this. I hope that others will jump in and help people that are in need.
2017-01-09: Flash script now backups original boot.img and system.img first.