There's only one way -- the same as with any other custom content you want to remove from the game.
Take the file out of your My Documents--EA Games--The Sims 2--Downloads folder.
If it still shows up in the game after that, then you have a duplicate(s) of the file and must take that/those out of that same folder. Or you may have inadvertantly put the Insimenator file into another game folder (where it doesn't belong in any circumstance) -- should that be the case, remove it from there.
OH okay. I'll do a search through my files and see if imaybe there's a duplicate.
Babu