how to make an hole into my object? I have an 3d skull face and I got my eyes and nose merge into it. But I can't an hole into my face like carving my nose and eyes. I think it's because I fill my skull face with the beautify grid before merging element. Anyone have any idea how to do this? And with the beautify grid it didn't cover up all the face of the skull do you guys know how to fix this ? 
Here's a gif of my skull and what i try to achieve:



Thank you!!
It looks like you could use a Boolean Difference modifier to cut a hole into your main object.

In the gif it looks like the face you selected is connected to the object that is going to be used to cut a hole. In order to select the whole cutter object, select the face shown in the gif and press Ctrl+L. Then press P and separate it from the main object. Once separated, press TAB and go into Object Mode and select the object that is going to be cut. Go to the modifiers panel and add a Boolean modifier to the main object. Change the Operation to Difference and for Object select the object that is going to be used to cut the main object. Then press apply and there should be a hole in your main object.