Don't even give the instructor a chance to think that you are doing it. Use common sense. Things to avoid include:
Please note that various and significant precautions are taken to discourage cheating on exam regrades. For example, a certain percentage of exams may be photocopied before being returned. If it is discovered that you make a change on your answer before submitting for a regrade the case will be reported to the Dean of Students, without warning and without possibility of appeal, and the maximum penalty requested. This maximum penalty is permanent expulsion from UCLA. So please don't even attempt to cheat. The penalties are much too severe.