PB blaster is a very good solvent (spray, like WD-40) It is yellow in color, rust preventative, and some of the best penatrating lube ive seen/used. They sell it at any auto parts store, and even wal-mart.

As for the GP's the are not hard to r/r the 3rd and 5th are a bit challenging, but nothing that you cant handle. BTW- the wrench size is a 12, if you didnt already know.