[Imp]

Firstly I assume by MOBHACK you mean non standard OOBs.
It is common for uninstalls to leave user defined stuff behind.
Your Preffs Game saves modified OOBs etc would all fall in that category.

Back up anything you want like maps pref file,
Now uninstall & use explorer or whatever to navigate to the MBT folder & delete it.
If you have Vista your game saves may still appear if you installed in the program file directory, don't it only causes problems. Its not a problem just save over them as you play or delete them it does not effect the install though they may not work properly if OOBs have changed.

If you want to reinstall Plasmas mod suggest the following.
Re install & patch SPMBT
Now copy the whole folder somewhere else
Go to the folder & create a shortcut from the game options icon.
Rename it Coldwar or something & apply the mod.
You now have the standard game & the coldwar one