Begin by placing your watch face-down on a smooth surface (such as towels) that won't scratch the watch's face. Check the rear of the casing to find the tab or an indentation on the edges of the case.
Employing an inflexible dull tool, such as the flathead screwdriver or butter knife to gently lift the back cover away by squeezing the object against either the tab or indentation until it releases. You can also hire a professional person for battery replacement by simply typing the query ‘best watch repair close to me’ on the browser.
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If there's no access tab or indentation then you can hold the watch with a vise, set the tool to a place where the back cover can fit inside the casing of the watch, and then tap the tool using a mallet made of rubber. Take care not to cause damaging the cover or injury to yourself caused by improper tools.
If the battery is apparent, you can determine if it is secured by the bracket. If that is the case remove the bracket with the screwdriver found in the eyeglass fix kit.
Once the battery is liberated from any constraints then turn the watch upside down and gently tap it so that the battery will fall out. It is best to allow it to slide into the casing of the watch, instead of removing it in order to avoid damaging the internal components.
Be aware of any gaskets and washers that might be removed or loosened when replacing the battery. It is crucial that they are all put back in the watch exactly as intended to preserve the watch's functions and reliability.
Insert the battery into the watch in the same direction that the original battery was. Place it in the watch carefully and then replace any washers and brackets.