Is there a way to remove only on part of terrain not whole?[SOLVED]

Yeah I know I seem to be asking too many questions about terrain, but I cant really find anything about it. On roblox wiki there is a function Clear(), but it clears whole terrain and i need to remove just one part of it. Like say I want to generate cavs in my terrain, I have a position on where the next whole should be, but how do i make this hole?(Obviously not using studio terrain tools as I am doing caves in script)