A cracked or broken windshield, either in the front or the back, is a dangerous thing to be driving with. A damaged windshield needs to be removed immediately for replacement. The exact removal procedure can vary depending on the vehicle type, but it is always one that requires care and at least two people.
Breaking the Seal
If you're removing the front windshield, first remove the rearview mirror and wipers by removing their screws. Next is the metal or plastic outer trim, if the car has one, helping to hold the glass in place. This requires a special trim removal tool (any auto shop should have one) that you insert underneath the trim so it catches and releases the clips. Place a towel on the glass to prevent the tool from scratching the glass as you use it. You may also need to remove a number of screws that hold the trim with a Phillips screwdriver. Next is the rubber gasket. Check the condition of the gasket. If it's dry and cracked, you can't use it again, meaning you can cut through it (and will need a replacement gasket when installing the new glass). Carefully insert a knife blade into the gasket, making sure you don't hit the glass as you plunge it through the rubber. Cut all the way along the edge of the glass to the original point. If the gasket is in good condition however, you can remove the glass with it still intact. Run a large stick across the gasket to break its adhesive seal; this is only needed on the manufacturer's gasket.
Pushing Out the Glass
The windshield needs to be pushed out from inside the car, and you will need another person's help. While sitting in one of the seats, put your foot and the large stick up against the glass. Push the glass out of the window with both the foot and the stick. Do not kick the glass. Use extreme caution if the glass has been cracked; keep your foot and the stick as far from the crack as possible. Your assistant should be positioned on top of the hood, ready to catch the glass as it pops out of the window. If the gasket is still intact and in good condition, pull it off the glass so you can install it on the new glass. In most cases, it's best to get a new gasket. If you cut the gasket, its outer edge is likely still attached to the window edge; remove the remaining piece from the window. Be sure to clean the edges before you begin installing new glass.
