There are several threads here on the forum about replacing door hinge pins and bushings. This method makes it possible for
one person to accomplish it in under 30 minutes, without doing a balancing act on a rolling floor jack, or scratching the door and fender in the process! There are two very inexpensive tools that make this a real easy one man job. The first one you may already have in the garage, a 2" wide ratchet strap like this:
The second is a GM door spring tool, it looks like this and Harbor Freight has them for under $10
Open the door, disconnect the wiring harness connector that goes into the door. The connector is just above the kick panel. Feed the harness, the connector, and the rubber grommet out of and clear of the body. Toss one end of the ratchet strap over a joist in the ceiling, keeping it directly over the door frame. Roll the window down and feed the strap through the window opening. Connect the hooks together on the ratchet straps so you have a loop over the joist and through the window opening. Tighten the ratchet enough to remove the weight of the door from the vehicle. You'll need to find the balance point for the door by moving the strap a bit during the process. Remove the spring. Remove the hinge pins. Remove the door. Remove the old bushings, clean up the hinge frames and put a gob of grease on each of the new bushings to hold them in the hinge frames while you install the door and new hinge pins. The trick is finding the balance point. Once you have it, you can move the door into position with one hand and put the hinge pins in with the other. Nothin' to it.