- 1). Establish whether the watch has a snap-back case or a screw-back case by turning the watch over and looking at the case back. If it is smooth with a small indent on the side, it is a snap-back case. If there are several small slots on the back of the case, it is a screw-back case.
- 2). Use the flat blade of a small screwdriver inserted at the indent to gently pry open the snap-back case back.
- 3). Use the blade of the screwdriver to turn the slots on the case back and open the watch with a screw-back case. Alternatively, use a case back wrench, which has several small tips that are inserted into the watch slots and turned simultaneously to open the case back.
- 4). Remove the battery and replace it with a new battery. Watch batteries can be purchased at most grocery stores, drug stores or watch repair stores.
- 5). Place the case back on the watch and line up the indent if it is a snap-back. Push gently on the case back once lined up to close the watch.
- 6). Use the case back wrench or the screwdriver blade to turn the slots on the case back and close the watch for a screw-back case watch.
- 7). Wind the watch if necessary.
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