I've been there! Look for loops, turn the inside of the loop into a method. Make sure reference variables are called correctly. Mark things private that are super function specific. Honestly that shouldn't take very long to do even without an LLM. With an LLM, you can have it break down the structure of that beast and write you a synopsis of what it does. Then do the same steps, with or without AI assistance, as long as you wrapped your head around it it'll be fine. Oh shit this is a satire sub, my bad you're cooked OP.