First, use a butter knife. Second, screw that board down so it doesn't come up as you pull. Third, using the knife come in from the side and pry the latch away from the connector. Once its away you should be able to just pull the 24pin connector away.
If the butter knife is to thick, try a dull steak knife. This isn't that hard to do. If you have any smart small children around you can ask him/her and see if their fingers are small enough to do it normally.