Most watches are now battery operated, but they come in two main styles. One style is analog with hands showing the hour and minute, and one style is digital with a liquid crystal display (LCD) showing the time, date, and often other information. Some watches are an analog watch combined with a digital display. Refer to both sections below for that type of watch. Changing the battery in most watches is an easy task.

Pull out the stem of the watch gently until it moves out one or two clicks. Be careful. The distance it moves out is not much more than the thickness of a thumbnail. This will stop the watch.

Remove the back of the case by unscrewing it or by prying it off with a small knife. Backs that pry off always have one small area raised slightly to allow a knife to slip under it.

Replace the battery with the same type that was removed from the watch.

Replace the back by screwing it on or snapping it back in place. Be careful to properly align any small rubber seal under the back.

Rotate the stem to adjust the hands to the correct time. If the watch also has a date and day display, push the stem half way in and adjust the day and date. Rotating the stem one direction changes the date and rotating the stem in the other direction changes the day.

Push the stem in all the way, and the watch should start running.

Remove the back of the case by unscrewing it or by prying it off with a small knife. Backs that pry off always have one small area raised slightly to allow a knife to slip under it.

Replace the battery with the same type that was removed from the watch.

Replace the back by screwing it on or snapping it back in place. Be careful to properly align any small rubber seals under the back.

Adjust the time and date according to the instructions that came with the watch. The watch will start automatically as soon as a new battery is inserted.