Very Carefully! Here's how I got mine in... Windshield: It will take two people to do it without breaking the glass. Run a small bead of windshield sealer goop in the bottom of the glass channel. Get some tough cord or string to put in the channel of the new rubber. Make sure you leaver plenty to get hold of at the top and bottom towards the edge where the windows meet at the center divider. Place the rubber around the glass before putting it in the cab opening. Put both pieces in and have your helper assist in moving to the cab. Place the new glass in the channel at the center and in both the top and bottom grooves of the rubber channel. Work on either the right or left piece and put it in before working on the second piece. Push firmly into the center groove and make sure the rubber is over the pinch weld so the inside cab flap is covering the pinch weld. Carefully have the helper push the glass from the outside using flat palms on the glass to evenly distribute the pressure, while you pull the string towards the outside direction of the glass from inside the cab. I worked the bottom in first, then the top. I also used silicone spray along the inside rubber lip to help get things to slip into place. At some point the cord will pop out from all the pulling before the window is completely in place. Don't panic. Now take a flat blade screwdriver and/or a 1" putty knife and use it to gently pry the rubber lip over the pinch weld while your helper gently pushes the glass down. Take your time. It took us a couple of hours to get both pieces in place, but we didn't cut the rubber or break the glass. You will undoubtably get some window sealer on the glass and cab parts. This cleans up readily with paint thinner (mineral spirits). I then went to the outside of the cab, gently pryed the edge of the rubber seal back where it met the cab and added additional dealer to the seam all the way around. My glass did not fit real well in the corners, so I filled the gap in the corners with window sealer, as well, and molded it with my finger to make it look better. Again, clean up any excess with a rag dipped in paint thinner. Keep changing the rag position to avoid spreading more goop than you clean. It's a bit messy, but it worked for me. Rear Window: Here things are a bit different. It will still take two to get the window set, but the window goes in easier. Do not use the window sealing goop on this install. Place the window in the rubber and make sure it is wrapped all the way around. It is very important to not stretch the rubber when installing... let it flow around the window. Cut the end where the rubber will meet itself very squarely to get a good face to face contact. I did apply a little goop to help seal this point. I had my ends meet at the center of the bottom of the window. Have the helper push the window from the inside of the cab while you pry the rubber seal over the pinsh weld on the outside. This will go fairly easily and should only take a few minutes. Next take the rubber locking bead and install it. I did not have the special tool to run the bead, so I fiddled around until I found what worked with what I had. I used a broad flatblade screwdriver in the groove a little ahead and under the locking bead to open the channel. Next I used a brake adjusting tool which has a very broad and flat face to push the bead into the small piece of channel that the screwdriver opened. I just worked around the window this way to get the bead in place. Take care to not stretch the bead when inserting. I would periodically push hard against the bead that was already in the channel to compress it into the rest of the bead. The reason for this is that if you stretch the bead while inserting, over time it will pull back to its original dimension and you will have a gap in the locking bead. It is better to have to compress the final tail into place than try to stretch it to meet. Here, again, using liberal amounts of silicone spray helped get the bead to slip into the channel. Be a bit carefull with the tail of the bead.If you let it pull on the part you have in the channel it's weight can pull out what you have already inserted and you will have to start again. Once you get to where the bead meets itself, cut it square and insert the final end. I hope that helps. It worked for me and I had never done this before. I got some ideas from the shop manual for the 1948 - 1952 trucks. I recommend getting a copy if you can. The rest is just finding what works. I am sure there are others on the site who have easier or faster ways to do it.