Lift up on the arm till it hits the stop.
There is a little tab on the side of the arm, slide this away from the arm. If you can't do this with your finger, use a screwdriver between the arm and tab. Should not be terrible difficult to move.
Once the tab of moved to the release position, the arm will remain away from the windshield when released.
Wiggle the arm while pulling up. If it does not release, a couple wacks with a rubber mallet will usually break it free.
I'm never used a special pulling tool to remove them.
1999 Astro (Green the Daily Driver) - 2WD, 3.23, 265k+ miles, FE2 steering
1997 Astro (Grumpy the $250 Rally Van) - AWD, 3.42, 2" lift, 31" tires, 339k+ miles on the orig eng
, $30 eBay fuel pump
1980 Kawasaki KE100 (Bessie)
2002 Jeep Liberty (Eugene the Wife's Toy) - 4.10, 4" lift, 31" tires