Most of these watches need the back prised/popped off with a small watchmakers screwdriver or small sharp knife. If you look around the case you will notice a small indentation or slot, (often near the lugs for the watch strap) so use this slot place your tool to lever off the back.
On more expensive watches the back may be threaded so will have to be unscrewed.
Pete
August 2008
Automatic Answer
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