just got a gen3 fossil q explorist, stuck on boot loop

purchased a factory refurbished gen 3 fossil q explorist, paired to my phone and was running updates, left it overnight on the charger and now it is stuck in a boot loop, tried to hold power button but it just resets to the loading screen. cant find any info on how to open the back to try and disconnect power as it looks different from gen 2s or others and has no screws