Nut splitter, a pair of Vice Grips, and an adjustable wrench will do the trick. Doing it yourself you will come out ahead as opposed to taking it to a shop and you will have a few more tools to boot . Spend the money on stainless steel nuts/lock nuts, bolts, and washers/lock washers when you put on the new plate. I would not mess around with the plastic nuts. Do it right the first time and you will not have worry about it again .