they are glued (and more)! take a sewing needle and work it into the top until you can pry a small space between the cap and the housing, then stick your finger nail in there or something thinner, and pull. It's weakest at the top cause at the bottom there are 2 tabs stuck and glued into the casing. Warning you, you're probably gonna break the tabs when you pry it off.
see my other post http://forums.ilounge.com/showpost.p...78&postcount=5