Just go up to them and beg them. Just don't take no for an answer. Tell them that you need the grade to get into dental school to support your single mom on welfare, and 6 siblings.
If it comes down to it, tell them you'll kill yourself if they don't change the grade. You're the last hope in the family and if you don't succeed, then you're just a burden to them.
I've used this method a couple of times, and it has been proven to work every time. And my parents are middle classed, living together, and I only have 1 sibling.
If you're not cheating, you're not trying. It's all about who WINS in life. The Patriots cheated, and they're champions.