My phone is overheating always

@joy60807 could be the battery or could be issues on the main board. It will depend on why and where it overheats as well as how your phone functions. You have not provided those details.

Since iFixit does not yet have a guide for that, use the one from here It is written in Spanish so use a browser that will translate it for you, if needed.

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 a device with the same issues as you do. 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!