How to Install mods and maps?
You need a program to extract those files. These are the most popular ones.
WinRAR: (I use this one.)
Once you have installed one of those programs, extract the files to the RTB folder.
1. Double click the file.
2. Click "Extract to".
3. Find your RTB folder.
4. Click "Ok"
If you need to overwrite some files, click yes.
Congratulations! It wasn't so hard afterall, eh?