If they are the ones I think you mean, poke a hot soldering iron through the bottom of them and they will come out easy. You can put them in the same way, but I usually straighten out the 'flare' on the top and use them like that (ie they can easily come out next time).
Another method that I don't like is drilling. This is described here:
http://www.classicplayfields.com/f2khelp.htmlcheers
Ian
