rear wiper replacement

I am having trouble replacing the rear wiper on my 2003 MPV. The instructions seem pretty stright forward on the replacement wiper arm, but I can't figure it out. The instructions say to angle the wiper at a 90 degree angle and remove, but the plastic housing piece that connects the rear wiper to the window hinders this. I am not the most handy fellow, but this seems well within my skill set. Of course, maybe not, given my results.

Any help is appreciated. Thanks.