Getting to the inner workings of a Techno watch can be a major expense, especially if you don't have the necessary tools. Accessing the batteries requires a specific set of tools, depending on the shape of the casing. If the watch case is polygonal, you need a polygonal case opener. If the case is circular, you need a circular case opener. Without these tools, you won't find an effective means of accessing the watch case without damaging the finish or the bezel.
Items you will need
Bergeon 5338-1 F Case Opener (for polygonal cases)
Bergeon 5337 Case Opener (for circular cases)
Strip of linoleum
Place the watch face-down on a non-abrasive surface that will hold the watch in place as the case is unscrewed. A strip of linoleum is ideal.
If the case is polygonal, position the Bergeon 5338-1 F case opener over the watch case. The tool will grab the corners of the case. Press down with considerable force and turn counter-clockwise.
If the case if circular, place the Bergeon 5337 case opener over it. This case opener must be pressed down and turned counter-clockwise simultaneously.
Remove the watch case.
Use your thumb or fingers to slowly unscrew the watch case until it's completely removed.