I have experience using oclp. The steps are listed on the website, and when you download the patching app, it guides you through the steps, too. But read through the site first. It’s relatively simple and most of the complicated work is automated.
But changing out the internal parts of any MacBook after 2015 will be a mess of soldered- and glued-in parts that it’s best to get changed out by a vendor trained to do it.