I'm cleaning a Microsoft Sidewinder X6 keyboard, and am trying to remove its plastic "case" (that part that surrounds the keys) and rubber padding (under the keys) to clean them. However, the case doesn't come off because I'm noticing a lot of resistance in the position of the wrist rest (shown with red box in attached photo). That made me wonder, is this case even removable? Should I try harder? I just don't want to break anything.