Saab Rear Winshield Wiper

How can I remove the rear wiper on a 2000 Saab 9-3? The entire arm is loose on the shaft of the motor and does not work. I cannot find a set screw or way to remove it.

On some cars the lower portion of the rear wiper arm pivots up to reveal the nut that attaches the arm to the shaft.

Remove the cover at the base of the arm. You may have to get a puller to remove the arm. The wiper arm is a press fit that is held in place with splines.

The base of the wiper arm is a cover. Once I lifted this there was a nut that needed to be tightened. The wiper arm fit onto the splines of the motor shaft and then is held by the nut.

Thanks for the suggestions and help.