I know takes a great deal of coding, and most of the time images are needed so the changes will show up. But what programs do you guys use to see the texture and model files? What do you use to change them?

I'm currently taking a "crash course" in coding from a friend, and modding looks like fun and might be good practice for me. How do you guys do it?

There was another guy asking about eggs in the "suggestions" thread again, and then I saw someone else asking about changing the resources needed to make boulders. So I'm thinking, why not just put an "egg skin" on a boulder? And how do you guys make those amazing murals I see when I go lair exploring?

Btw, I looked through all the "decor" files in "resources" I could find- where exactly is that boulder?