How to repair the volume button

@fahad57466 check for any dirt or debris that may prevent the button from working. Cleaning it may help. If that still did not resolve it you may have to change the power/volume flex cable. You are looking to replace a flex like this

Since iFixit does not yet have a guide for that, use something like this video to work on it. While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.