I don't know how you remove it, but you can buy a replacement from Service Tools in the UK tel 01925 251700. I enquired about this same part today (5-11-08) they quoted £39.36 which includes VAT and delivery. (I am actually looking for only 3 keys and mechanisms--K, L and X---so if you have your old keyboard spare after replacing it maybe we could do a deal?
chris_livingston@hotmail.com, November 2008