As Paul said, WD40 and lots of brute force. The same thing happened to me sort of, well it was stuck in ridiculousley tight anyway. But i ended up using a vice, a hammer, and a blunt object of some description. Then once it was half-way out i use the vice to hold the pin, then I got another vice to hold the rest. Then i gave it a few good old wacks with another blunt object and that seemed to dot he trick.
