Hi to all.
Mine started to blink BATT to indicate low battery, so i searched and searched for instructions...
All i got from google was stories how to sent it to Tissot for couple of weeks and with high costs.
So i grinded my old srewdriver fit exactly to those four srews on back, and took backplate away.
Eeeww lot of dirt, DO NOT touch to pressure sensor.
Then another backplate with pressure sensor off...
... and i can see the battery.
It is just ordinary 2032
After cleaning assembly in reverse order and done.
Ps:I took these pics with my cellphone so sorry for quality, but you can click those to enlarge full size.