DIY : Open the back of a watch with this simple technique - Duct tape

You do not need special tools ( could scratch ), just a simple Normal duct tape and chopstick to hold on and turn. It maybe use to open bottles' lid etc. Maybe you can use other tape that you have at home. Won't work on smaller watches because the surface area of the back. Also note, if you do send your watch for servicing, inform the shop keeper not to over tighten the back lid ( most of them do ). This causes the rubber to deform and also, the moving parts (for kinetic or automatic ) might hit the cover's inside.