If you've saved when you've already been to that module, and don't want to have to, for example, replay the entire level, you can follow the instructions in this thread. (
http://www.lucasforums.com/showthread.php?t=150955) In the save file, look for the module with the same name as the one you're editing, and delete it. It should then rebuild that module. I had to do that to get one of my mods to work after I made some changes.
Just make sure to back up the save before making any changes like that.
The first time through, it froze up on me trying to load the save, but I think I might have had the game open when I was making all my changes. Anyway, I rebooted and it worked fine.