This is a form of “How do I make a (any large project)?” question. The answer is that there is no easy way to do that, and there is certainly no one right or wrong way, either. You will simply have to learn about the relevant parts of the engine and then make it work how you want to. So, dive in and start trying to make it happen, and come back when you have specific questions about the part of the engine you are working with.
Good luck! You can do it!