The best way to remove a stubborn wart, I've found, is to use a combination of a good wart removing solution (generally something containing Salicylic acid) in tandem with a small block of pumice. Apply the acid when it's convenient to walk around with the wart bare for a while, and allow the acid to soak in and dry. This will painlessly kill the excess skin which composes much of the wart. Do this once or twice every day.

Meanwhile, leave the pumice in your shower stall or bathtub, and near the end of each shower or bath, scrub the wart vigorously with it. Your wart should be gone in about a week!