http://users.rcn.com/kochc/moto/carb/carb.html
Great article on carb cleaning...
If you dont want to get too involved, I would dump out the gas that's in there, fill the tank with 1:1 seafoam and fresh, non ethonol, oil mixed gas, and try to start it. After a few pulls, just let it sit, come back in a few hours and try to start it again... Should run after that. May not run right, but, it should clean itself up fairly well after a bit of running. If not, just dissassemble the carb, scrub it with carb cleaner, and put it back together. Try not to loose anything
~Nate