I want to convert a esp to esm, which I've never done before.

I noticed an option for this in Enchanted Editor, and so I clicked Master file option, but the extention is still esp. I renamed it to esm, and it loaded fine in the CS, is this all I have to do?

Thanks in advance.

Wrye Mash has a "Copy to ESM" function, It can also convert esm > esp, too. I bet you're using that program.