I have removed and installed about 30 windshields and its not that hard to do without cracking as long as you have the right tools. You need to grind some piece of metal wide to a fine razor finish then bend  it to a 90*, fix it to to a screw driver or a stout handle and drill a hole or tack a weld just above the razor so you can pull it with a makeshift hook, and thats where you break through the polyurethane bead. Heat can help tremendously. At no point should any force be put on the glass. I have used a pneumatic air hammer with a thin paint scraper attached  to it, but that has to be done with extreme caution but highly effective.

Now for install, make sure your surface is clean, you must remove all the previous polyurethane, its a pregnant dog but just keep scraping at it. Clean ALL the area that the new urethane will be touching, very important, use contact cleaner or brake cleaner and wipe it good. Now a cordless caulk gun is the absolute best way to put a clean bead down but they are hard to find one laying around, so if you are doing it manually, practice. You can buy polyurethane at a auto parts store.

After the windshield is in place tape strips long ways to avoid the windshield from sliding down, takes a solid 2 days for it to dry. DO NOT SHUT THE DOORS WITH THE WINDOWS UP! You will blow the bead out. Place tape over the window or open the rear window if applicable.

I hope any of this was helpful, and if you break it, call around to shops to see if you can get a good deal, chinese windows are cheap, but they are cheap. Good luck