Nails??? You gotta be kidding, you spend thousands of dollars on a truck and then use nails instead of getting the correct 59 cent cotter pin:--)
To pull cotter pins, use a pair of diagonal side cutter (dykes). Grab the eye of the cotter pin as deeply into the dykes as possible, squeeze gently (don't cut the eye off) and lever the ends of the cutters against the flat of the nut, when the pin moves, slide the dykes down and get a new bite. Stainless cotter pins can be removed without even trying to straighten out the bent ends, using this method (works on airplanes).
When you get the cotter pin out, use the closest trash recepticle as a storge facility for the used cotter pin. Spend the cents and get new pins before you start the job.
Sorry for the rant