Simplest way to modify the engine code?

Ok so I have a very specific issue that can (potentially) be fixed with a small modification to the engine code, specifically, forcing a variable to be always true in the Static Mesh serialization.

I looked into making a plugin for this but it seems both tedious and necessary for the changes I want.

So the question is: what is the simplest way to modify the engine code? I feel kind of lost here. It seems it should be pretty easy but I cannot figure it out. I have already made some custom C++ classes but this is different. Is there a way I can just tell Visual Studio to Rebuild the engine with modification I made?

Thanks in advance!

The easiest way might be cloning the Engine from Github and changing whatever you want to change and compile it.

Another approach might be creating a custom Engine, this is a short tutorial:

I hope it helps.