use a blunt round ended old table knife, push knife in and twist a little to open. Scrape the top of the shell (about in the middle) to remove the Foot which is the hard white muscle attached to the top. Then open up (easy now) and use the same tactic of scraping under the body of the muscle to release the other foot from the bottom. It'll drop out then all in one piece ... :0)

well maybe........

it gets easier the more you shell.
norm