If and only if (iff) you have a broken phone, then you do not have to hold a philosophy doctorate (PhD) in Computer Engineering, in order to fix it, "nope." All what you need to do is: looking at the following lines, brought to you for God's sake (no money) by the iMadhoob pico-laboratory.
Attention: this tutorial is for experimental purpose only!
Before starting you need to get some stuff:
1- Little or no experience in tinkering, but familiarity with screw-driving.
2- A bunch of bucks ($$$) to give those Chinese guys on eBay.
3- Vitamin P for patience, as you know "time is money".
4- The broken phone, so be patient and don't throw it out.
5- You, you need to own your-self (thanks to God for that gift).