How to replace power button

@giftlangali you are not giving us a whole lot of detail here but the most common issue with a failed power button is the power button flex needing to be replaced. Since ifixit does not yet have a specific guide for that, use the one from here It is written in Spanish so you may have to use a browser that does the translating for you, if needed.

The flex is readily available at many online 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 that has the same issues with their phone. 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!