Close the door. Place the tip of a hex-head screwdriver beneath one of the pins in one of the hinges. Tap the handle of the screwdriver with a hammer until the pin lifts up. Grab the top of the pin with a pair of pliers and pull it out of the hinge.
Put on a pair of rubber gloves. Lay some paper towels on a table. Hold the pin over the paper towels and spray it with a rust removal cleaning solvent. Scrub the pin with steel wool to remove all rust and corrosion. Spray it again to remove all grime. Wipe it with a paper towel.
Smear motorcycle chain lubricant over the pin. Slip the pin back inside the hinge. Tap it down through the hinge with the hammer.
Remove another pin and repeat this process. If the door has more than two hinges, then clean, lubricate and replace the second pin before removing the third. Open and close the door several times to allow the lubricated pins to work on the hinges.