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).
First of all, go to www.ifixit.com (or anywhere else) to make sure that they have a free repair manual for your phone, then move to www.ebay.com (or anywhere else) to make sure that they have the replacement parts needed. After getting your bill of materials (BOM), return to www.ifixit.com and start the operation.
You need to get a lab cleaning brush to avoid electrostatic discharge (ESD) and some tweezers:
It is recommended to use a lab coat and an ESD wrist strap (or ESD gloves):
Optionally, you can make use of those old chess boards:
A cup of Arabian coffee to be awake:
You should receive a package contains all replacement parts and tools:
Now, go to www.ifixit.com and follow the instructions:
Finally (if no problems), you will have your phone ready: