How can I delete grass texture from Terrain

Hello, I have cover all the terrain with grass texture. However I want to add other textures as well, e.g rocks but grass covers everything. Is there a way to remove grass texture in specific positions of the terrain? (I don’t want to create the terrain from the beginning again).
thanks

Really out of time, but if it can help anyone, hold shitf and then click to erase tree, grass or detail. Greetings.

Add different textures and after you selected texture brush, select the texture you want to paint below them, the textures you added to terrain will appear as a box in a rectangle.