How to change Battery

@rajendarbandari since iFixit does not have a guide, yet use the one from here It is written in French but Chrome and other browsers do a pretty good job of translating it.

Replacement batteries are readily available online. Just pick a vendor that appeals to you.

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.