How do you remove rear wiper arm from a Hyundai Santa Fe?

I just replaced the complete rear wiper arm on my 2010 Santa Fe in 5 minutes. In my situation, the arm was completely broken off and the plastic cover to hide the bolt was also missing. I only had a little 1" stub of arm remaining bolted to the attachment stud. All this was due to an automatic car wash breaking off the arm and cap.

The stud under the arm is very slightly tapered (smaller at the end closest to you) and is splined to keep the arm from twisting when in motion. There is a black/plastic or metal ring (washer) between the rear window and the wiper arm. I removed the old arm by taking a thin, slot screwdriver and placed it in the narrow gap between the arm and the black ring , then gently twisted the screwdriver to wedge-off the arm. The arm just fell off. Ta daa. Now just bolt on the new arm and you're done.

Note that the plastic cap, wiper arm assembly and wiper blade cost me after tax $97 in Canada. I will put the free little plastic bag on the rear wiper arm before auto car washes in the future. I always thought the bags were useless.