look for a little clip at the end of the arm where the wiper blade slides over pull up on the clip it should slid right off.
1991 Corsica its under the trottle body
The 1991 Chevrolet Caprice wiper blade sizes are 22" wiper blades on both sides front and a 16" rear wiper. See sources and related links below for more information. Since there are over 22 different wiper arm attachments, do not buy wipers just by length only - be sure to lookup exact wiper blade part numbers by vehicle make, model and year for the brand wiper you decide to purchase. This ensures correct length AND correct attachment.
The 1991 Ford Aerostar has the most common hook-end wiper arms. See sources and related links below for installation videos. Locate and press the tab or button where the wiper blade is inserted into the hook of the wiper arm and pull wiper blade out of hook. You may have to rotate and flex the blade to make enough clearance for the hook to pass through.
For a 1991 Chevrolet Corsica : My Chilton's Auto Repair Manual shows : ( 15.6 U.S. gallons )
It doesn't have one, it is distributorless.
Assuming that you mean wiper blade (blade and frame) rather than wiper arm (piece from the spindle at the hood to the wiper blade), the 1991 Oldsmobile Eighty Eight has the most common hook-end wiper arms. See sources and related links below for installation videos. Also, purchase the replacement blades first and there will be additional instructions/illustrations on the replacement packages. Locate and press the tab or button where the wiper blade is inserted into the hook of the wiper arm and pull wiper blade out of hook. You may have to rotate and flex the blade to make enough clearance for the hook to pass through.
13.6 gallons
When you purchase the new wiper blade the package has detailed instructions on it. Or you can get the parts person who sells you the blade to change it for you. I have changed many blades for customers.
Green coolant (prestone, etc)
You have to take the door apart
Was there a 1984 Oldsmobile Cutlass Calais? I see them listed at 1988-1991. Assuming that you mean "wiper blade" (blade and frame) which are replaced often rather than "wiper arm" (piece from the spindle at the hood to the wiper blade) which are rarely ever replaced, ALL 1988-1991 Oldsmobile Cutlass Calais' have 3/16" Side Lock wiper arm attachments. See Sources and Related Links below.
Depends on which engine it has. Try a Google Search.