There are many different types of watches, but a general way you can use on how to change a watch battery.
Remove the Back of the watch
The two main types of watch backs: non-waterproof and waterproof. Usually you will not need specialist jewelry tools on how to change a watch batter.
Non Waterproof Watches
These are usually how to replace a watch battery involves the easy removal of the back by inserting a blunted knife along the rim of the back. Flip upwards and the back should pop off. Sometimes there is a rubber ring around its interior rim. This ring should be replaced with a new one but as long as you are careful and it is not damaged you can replace the original rubber ring.
These will have to be rotated in an anticlockwise motion to unscrew them from the body of the watch. There are specialist tools for doing this with a range of inexpensive adjustable removing tools. It is best not to attempt it without one of these tools. It is possible that you may break the pressure used to keep the waterproof seal. Using a tool to removed the back of a waterproof watch is how to change a watch battery properly.
The Watch Battery
The most common watch batteries are V371 (quality men’swatches) and V377 (quality lady’s watches and most cheap made in china movements). Nevertheless, there are a large range of batteries which vary in size and voltage. The battery can usually be identified by its number on the top side of the battery. Please always ensure you have the right battery as sometimes the same sized battery can be of completely different voltage and amps output. The top of the battery is marked with either a + (positive) or a – (negative).
How to Remove The Watch Battery
How to change a watch battery depends on whether the battery is screwed into its base or is merely held in place by a clip around it. If its the later then you can gently place the edge of a small flat screwdriver underneath it and gently flip it up and out. If it is retained by screws you will have to unscrew them taking care to remember their corresponding location.
Change a watch battery. Insertion is a straightforward reversal of the removal operation. Care should be exercised to replace the battery with the same side facing upwards. (98% of watches have the + side facing upwards). Also try and use a pair of non metal tweezers. The image shows the use of a plastic clothes peg holding the battery over the bay in which it sits. You can then press down with a plastic pen or similar non metal object.