Can I change world difficulty without making a new one?

[JFK_360NoScope]

I have a pre-hardmode singleplayer world that I made but I want to change it to master difficulty instead of expert. Is there a way to do this via files? I put a lot of work in this world and don't want to have to make an entirely new one.

[Jesus F. C.]

Probably, should just be a matter of digging through the files

[Marshmallow]

TEdit can change world difficulty, not sure if you can do so through the files due to never having tried to myself.

[Cube]

World files are very hard to read, if even possible at all without third party tools, so editing even small details like difficulties wouldn't be easy. Like the person above me said, you can use TEdit to load the world and it is very easy to change difficulty from there, but other than that, I can't say it is possible without making a new world. Pre-1.4, you couldn't change your world name without TEdit, which was a pain, but luckily they fixed that. I understand not being able to change world difficulty though.