Personally, I use the UnRen.bat tool whenever the game I'm making a mod for (walkthrough, unlocking, cheats, etc) only includes compressed (rpa) and compiled (rpyc) files. The tool allows me to deconstruct the game so I can make the necessary modifications. I also make sure I do this on a separate copy of the game's release folder, just so I have a quick way to reset (if I go modding too far), and/or so I have the original release files to test my mod with (to make sure it performs correctly and without errors).
Quick tip, btw: Avoid asking technical questions on how to do some specific modding stuff (or the tools) in game threads in general. Keep those questions to the tools' own threads, looking through one of the other forum categories (like Dev Help or Cracking), or even your favorite search engine (Google, DuckDuckGo, Bing, etc).