I haven't done it but from what I've read you have a choice - save the glass or the rubber gasket. (Both are fairly expensive...) If the glass is cracked but the gasket is good then break the glass out and save the gasket. If the gasket is defective but the glass is good then cut the gasket and save the windshield.
Also, I think I recall reading that you might need to remove the dash for best access.
The worst possible situation is you cut the gasket ($250 new), and still break the glass (which is reportedly easy to do and will set you back another $400 or so, IF you can find one).
This scenario plays out in my mind every time I think about removing mine to repair some rust on mine. I hate to admit this, but I might just drill out the spot and patch with fiberglass... I know that's blasphemy but the thought of spending $1,000 to replace something that's perfectly fine just to fix a spot of rust that's half the diameter of a ballpoint pen on a car that's only for fun...
If you decide that it makes the most sense to destroy the rubber gasket... it only takes a few minutes to remove the glass. You'll need 2 tools: a utility knife, and a friend. This method applies to the one-piece rubber gasket. Don't know about the rubber and chrome variety.
The utility knife should be one of the designs that has the long one-piece blade. The type of blades where you break off the segments to refresh the blade's sharpness. I think Olfa makes this design, but Stanley Tools may offer this too. Let me know if you need a pic of this design for confirmation.
The gasket is an 'H' shape extrusion. Extend the blade to its full length, and lay it basically parallel, or flat to the glass. From the outside of the car, shave off the rubber that protrudes above the glass... but leave the 4 corners of the gasket until last. This will keep the glass in place until you are ready. You don't want the glass falling inward, prematurely, of course. Now, have a friend sit in the driver's seat and support the windshield as you trim off the top two corners. He can gently push and release pressure on the glass as you trim off the remainder. The glass panel should just swing forward and upward, now. If you left a bit of rubber at the lower two corners, that should help give you a 'hinge' during glass removal, and help protect the glass. You may want one more friend to help take the glass from the body, once you have wiggled it loose. Just to be sure it doesn't get dropped and damaged. Poof, you're done.
I've done a couple of these removals (5-10 minutes to complete, once you have everything in readiness). I've never replaced the glass, so I won't offer any advice there. That job goes to a windshield wizard, since I could only do bad things, there!
Don't take this as fact... but I asked a glass shop what they suggested. Since I was considering saving the gasket and glass to sell used, I had a different consideration than you. I had a buyer for the windshield ($200), but the gasket (maybe $89 used) would sit on a shelf until someone wanted it.
The glass shop said they could do the removal for $90 each windshield. They have a special metal tool and know the string trick. Based on the age of the glass (1986), they said they could not guarantee the glass would survive the surgery. Since the used gasket might be worth $90, and they wanted $90 to remove the glass and gasket (w/ no promise on the glass' condition)... I had to decide between saving the mother or the baby. And the glass was more valuable than the gasket. So, the numbers did not work for my purposes.
That was only one shop's assessment. So, if you can find a shop near you that can do this for cheaper, and/or can guarantee both would come out unscathed... your choice might be different than mine.
Don't screw up a good windscreen or gasket. This is easily removed with out destroying anything. I have done it a lot. The Gasket is Neoprene and very stable material. They usually don't go bad unless they are cut.
First: Remove the rear view mirror.
Second: Remove the trim down the sides of the windscreen on the inside.
Third: Get several paint stirring sticks and cut them into pieces about 4 inches long. Sharpen the ends if you want -a flat knife.
Forth: Get a few small screw drivers.
Fifth: Start at the inside center of the windscreen and lift the rubber lip off the headliner material and insert a wood strip (paint stirring Stick). Work your way to both top corners (from the inside) pushing the rubber lip back and locking it back with the sticks.
Keep going back towards the inside center of the glass pushing the rubber back until you can lap it to the outside of the headliner material and the metal edge that is under it.
Eventually, you can work your way down both sides and push the windscreen out from the top. The glass gets loose at a point that you can just pick it up out of teh body of the opening. It just goes.
Find a friend to help you lift the glass off the car - one of you on each side of the car - complete with the neoprene gasket.
Carry it away from the car and don't trip.
Note: The headliner is probably more valuable than the glass.
This will save it too if you are careful.
To reinstall, reverse the removal procedure. Take your time and don't pry anything to hard. Re-installation involves careful centering of the glass and gasket. Start by just setting it in place along the bottom seal, spreading the seal to get it spreading on both sides of the metal in front of the edge of the dash.
Probably not surprising, the rear hatch glass works the same way. Try it, you'll like it!
Installation is pretty easy, I used about 1/4in nylon cord (from an old washing line) laid in the groove of the gasket (started and finished at the bottom in the middle with several feet extra on both ends) and slowly pulled the cord out whilst applying a bit of pressure to the outside of the glass to help it seat. Being 6'4" with long arms helps, or get a friend to give you a hand.
After a few tries I had it in place and so far after 3+ years there's no leaks