How do you remove the wiper arms on a 2005 Jaguar XKR?

Assuming that you mean "wiper blade" (blade and frame) which are replaced often rather than "wiper arm" (piece from the spindle at the hood to the wiper blade) which are rarely ever replaced, 2004 Buicks will have various attachments. You'll have to determine which attachment you have by looking at them. Then see the Sources and Related Links section below for installation videos.