If you look at the base of the wiper arms you will see a little tab sticking out, pop it out about a 1/4 to 1/2 inch then pull the arm base straight out. If they have never been off you may have to coax them a bit with a flat bladed screwdriver [pry gently], the put some grease on the studs before reinstalling. I take mine off twice a year, once to put snow blades on and again to remove the snowblades and put the open blades back on.