Just kidding, but seriously the best penetrant is 50/50 ATF. However, if you care about your paint, maybe not. There is a sweet spot that seems to be different for everyone door. You have to slowly open the door back and forth to find it while lifting. Make sure you take the strap off and slowly open the door all the way repeatedly. Also hold the door from the far end with it open and try to work it up and down while doing this.
You can also try a jack with a block of wood to press on the door, or the pin directly if you can make that work. Just be careful to not crease the door or otherwise damage it.
If you still can't get it, you may need to get some help and remove the door completely, hinges included, and find a way to get some sort of clamp or press to work them out. Again, a risk of damaging the door. But you should be able to eventually work them off with the first method of penetrant and movement.
And of course, order new bushings (go with Delrin) because you won't want to reuse the old ones. Maybe remove the doors once a year or so (depending on your area) to keep them from seizing.
My 1st '97 TJ had a similar problem. I soaked the hinges with PB blaster and lifted up on the door while swinging the door open and closed. The worse of the two doors took about 15 minutes to release.
A work of caution, if you have a helper, this is easier with two persons. The person doing the lifting also has to make sure that when the door pins finally pop out, you don't accidentally gouge one of them into the paint on the Jeep (ask me how I know this).