HOW TO REMOVE THE PART IN SOLID WORKS?
I hope this helps and is what you were looking for.
Answered with a tutorial: https://grabcad.com/tutorials/how-to-remove-the-part-in-solid-works
Stephen Nyberg is right - a much cleaner model. The remodel is better than my fix - but you did ask how to remove / fix your current model.
The easiest way to remove the "surface"; add a cut revolve based on a converted sketch (the one used to produce the protrusion).
Another way It can be done is with a cut revolve and delete body.
Answered with a tutorial: https://grabcad.com/tutorials/how-to-remove-the-part-in-solid-works--1
Try this : Click under sketch > 3D sketch
Then click 'Convert Entities' and click the edges surrounding the area you want to remove. Once done, exit the sketch. Click 'Extruded cut' and select a plane almost parallel to the portion you want to remove. Enter a desired height and hit the checkmark. It should be gone. Let me know if it worked.