HaloMods "Classic" Read-only Archive

How exactly do I mod these maps? Everytime I try to (I'm using DotHalo) it says failed to load map, with or without fixing the encryption on the map. Is there a special way of doing this?

you didn't rename them anything did you as in like My containment mod because you just need to leave them the same and overwrite the old on your harddrive when u go to ftp it back and make sure u put it back in the right folder that you got the map from

You need to use a special resigner for it, that can't be discussed here. Just add it to your mainmenu.map.