How to fix the battery

@andilenzuza you are not telling us what is wrong with your battery. If you want to change the battery use something like this video since iFixit does not yet have a specific guide for that. The battery is a BLPA21 and is readily available at many places.

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 who has the same issues with their device. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!