Can't remove map NPC spawnpoints

hey can anyone help me im making an omaha beach battle project for my history class and i had it perfect but i forgot that the map had antlion spawn points too and i wanted to know how to delete those. (im on an actual HL2 campaign map) i think its called de_coast_3 or something like that but it has alot of bunkers and its a beach there are thumpers and i think its right after where you pass the lighthouse part where you take the secret passageway. anyway can i have help asap.