I didn't know how to describe my problem in the title, so I'll try to do it here. Below I have a project. I needed to take a small piece from the middle of the object, and I couldn't get sculping to work, so I just used knife tool and excruded after I had created what I wanted.
Now, when I'm finally rendering, I'm getting unwanted things on the render result, caused by these extra verticles. Is it possible to remove them? I tried making the holes new objects, but that didn't really work.
http://www.filedropper.com/blend1 (a link to the blendfile)