i recently removed a very stuck seatpost by putting a junk saddle on it and bashing it with a mallet. it took a while but worked.

for the pedal, go down to the hardware store and pick up a sturdy piece of steel pipe that will fit over the handle of whatever wrench you're using to remove the pedal. use it as extra leverage. probably best to tell the hardware store what you're using it for so you get the right sort of pipe.