Hi
Replacing an ESC is quite easy if you are comfortable witwith soldering and something you will soon become very familiar with in this hobby 
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Firstly its never a good idea to mix different ESC together, so of u want to get a new ESC, best to try get a stock wizard x220 ESC. Otherwise you will need to replace all 4
You will need to set it up again and make sure it all have the same settings in blheli configurator and that r motors are spinning in the correct direction. Also you need to calibrate them so they all spin at same speed.
Any other questions feel free to ask 