How to cheat and get free Bitcoin by changing the code.

Step 1. Change the code to give you free Bitcoin.

Step 2. Convince 51 percent of Bitcoin miners to use your version of the code that gives you free Bitcoin, and makes their Bitcoin now worthless.

It has been done before. The Bitcoin Cash fork is what happens when you change the code. Bitcoin Gold, Bitcoin SV, are all results of changes to the code, done by people that thought their version of Bitcoin was better.

By the way, it's written in Go, not C.