The negotiation with scholarship can be conducted in the same manner you would in buying a car. One thing I have learned in life minus a few exceptions, is that the advertised price of something is never fixed. First thing you would want to do is find some way that you have leverage over the school to make the negotiation. In this case, you may have higher scores than the schools average, or have several schools to choose from. When I submitted my scholarship negotiation letter, I reinforced to the school that I had several other schools to choose from and that many were offering more generous sums of money. At the conclusion of the letter, I basically stated that financing law school was a very crucial determining factor in my school selection process and that if they accepted my proposed offer, my decision would become rather easy. Put the ball in their court.
So, the great thing you have going for you is that you have nothing to loose. If they say, "No", then you are not worse off. Have some fun with it. I love negotiating prices.
Never pay retail or MSRP for anything!