My battry is not working. how to solves?

@danielbekele how do you know your battery is not working? If it is isolated to your battery and you have checked everything else, just go ahead and replace it. Since iFixit does not yet have any instructions for this, use the instructions from here Batteries are readily available at plenty of online stores.

If you have not checked the battery and can't say for sure that this is a battery issue, then you need to check two things. Your phone uses a charging board that has the charging port on it. Those like to fail and you should consider replacing it, if you do not have any power coming to the battery when you charge your phone. Also, The M-series uses a rather thick flex cable from the charging board to the motherboard. Those have a tendency to come loose. Check to make sure it is properly connected. For both of those parts, you can use this guide.

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.