I don't have a Dremel tool, but the bushings (at least the top flanges) on my current door hinges are pretty much wasted away and leaving a gap that a sawzall blade should slip into. I've got an angle grinder and everything else I should need. If I can buy the doors, that'll give me an excuse...
Thanks for taking the time to post all these pics, very helpful. Thinking of the same project myself. Saw a set of barn doors on Craigslist (mine are rusting out bad on the bottoms) and wondered how difficult to not only get mine off, but the ones from the vehicle getting scrapped as well.