I will be using a 1991 Ford Ranger. Yes she's is a little dirty.
Step 1: Keys On The Seat.
This will only work if you have left the window open a little bit.
Step 3: Access Device
Undo your windshield wiper by pulling on the tab and pulling straight off
Reach in through the gap in the window and hook your key ring, fob or in my case, lanyard, with the end of the wiper arm.
Pull your keys through
Replace the blade by pressing down onto the knob.
Open your door.