WinMPQ is a program. You can download it in oue tools section. Every map has an MPQ archive. So you open WinMPQ, then open the map as if it were an archive (you will need to have the file type set to "all"). When its open, upload the files into the open (the map's) archive. When the files are uploaded, you will then need to input the proper file paths (for skins and such).
Even if you have TFT, you can make RoC maps, and using the TFT editor to do this is MUCH easier. So I suggest doing it that way.
-VGsatomi