There are two main types of hinges I know of. The first one is the type that bolt to the door and the body. These can be removed by using a ratchet or wrench, and rehung the same way.
The second type I know as "Monte Carlo" Hinges. The tool is named the same for removing them. You do not need to have this tool for removing them however. First things first lubricate the hinge well using something like PB blaster. (It acts as a rust remover and lubricant. ) First try to hammer them out, using a long nosed punch.
If this fails, I use a die grinder / cut off wheel and cut the pins in two places. I cut a little below and a little above the middle part of the hinge. (Be careful not to grind or cut the hinge.) After this is done, you can use a long nosed punch and just drive them out. They should go pretty easy at this point.
It occasionally happens that the metal on the body where the hinges are get rusted out or saggy. To repair this, you need to take exact measurements of locations of both hinges and thier placement, it is best to make and use a template.
Use a die grinder, cut out the sheet metal that is bad. Check behind it, and ensure that the rust is gone. Now cut a same size and shape piece of fresh metal. Position and tack weld in the new metal. Use a hammer to GENTLY finish adjusting the location of the new piece and weld in solid. Use a hammer to flatten in the weld. Grind off and smooth down with sand paper. Use your template or measurements and and mark the center of your holes to drill with a center punch. Drill the holes. Clean area, prime and paint.
The monte carlo type hinges are pretty much the same process to repair behind the hinge if it goes bad. The difference these do not bolt on as above but are welded solid. These are more difficult by far to rebuild behind. First make your template and measurements. Next grind out the welds holding the frame side half of the hinge. Repair the panel as per above, except the holes drilling. These you need to TACK Weld in place enough to hold the door weight and be able to swing freely. Now begins the fun you need to line up the door again. This is simply a matter of time and patience and alot of hammering, grinding, and welding. once you can open and close the door smoothly and properly, you can weld it back solid again.
Now to hold the door for you, here is a trick if you cant get a helper. Take a 2x4 about a foot long. Screw 1x4 on both edges to make a |_| shape. Now pad out the inside of the |_| shape with foam. Place your new jig on a hydraulic jack. Now you are free to use both hands and not worry about getting tired before you are finished and messing up what you are doing.
Please keep in mind that although changing monte carlo type pins or the bolt in hinge type are simple, repairing the metal behind them is not simple and takes an experienced body / metal worker to do. Save yourself alot of frustration and take the car to the body shop if this type of work is required. The piece of mind is definitely worth the price. As is saving yourself the frustration.
The type of the two above it sounds like you have to me is the monte carlo type. Any auto parts store should carry them. The last ones I bought were 10-15 dollars for two pins, and all 4 bushings. I got them from Napa. If you want them from online, type in most any major auto parts store on google and you will find their website.
hope that helps.
