There's a single screw where the yellow arrow points to. Past that i'm clueless. I tried to pry it open from there but no luck.
BTW: the blue line shows how far my hydraulic arm extends in the parked position (about '2 inches too far)which causes wiper to hit window molding on each side. I think something went haywire inside, so I wanna take a look.
(thanks MBenz for the pic)