How do I remove a section of my part without causing errors?

I want to remove that section. Just the thick part, not the thin part at the back. I've tried a few different things and they all cause errors.

Message was edited by: Eric Eubanks Updated attachment to version that might be easier to edit in the way that I wanted. I have sketch 2 like I want it. Now I just need to fix sketch 1.

SolidworksParts And Features