HaloMods "Classic" Read-only Archive

I have searched and did not find anything about this so I was wondering how do I delete or remove triggers in single player levels? This should be possible but when I click on the trigger in spark edit and try to delete the trigger, it does not delete. The reason I am asking this is because I was following this tutorial......

http://home.mchsi.com/~halofreak/tutorial.htm

That is an incomplete tutorial that serves as a building block IMO. As for triggers, ask around on IRC.