I totally disagree with what they did. WAY TOO MUCH SEALER. All you need sealer for is to fill the small irregular areas in the metal flange from spot weld distortion. If you hammer and dolly this area and grind any rough areas it does not take much. Him putting that huge bead of sealer in where the trim goes is why it is so difficult to get the trim off and on.
I get my sandpaper and stuff from this place lots of places to get stuff.
https://www.autobodytoolmart.com/searchnxt.aspx?keywords=glass%20install%20tools
You will see they sell tools for removal and install both. You also need a trim removal tool to lift the clips enough to let the trim lift out. Never force the trim should come right off when you get the clips loose. I use only plastic trim removal tools or wood dowels ground down around the glass. The clip tool is steel but never touches the glass.
Like someone stated I would cut the old rubber seal out. Daniel Carpenter usually makes the best rubber parts. I am not sure if he makes ours.
With the glass out it is obvious you need to clean glass and the channel on the body. I would never use the foam tape the factory used. 3-M is down to one windshield sealer that does not harden. The video showed him using 3-M strip calk in the rubber channel for the glass. It is too thick and I just make a tiny hole in the end of the 3-M sealer tube and put a tiny amount in the channel that the glass goes into. A helper is always good to hold the rubber as you put calk in and slip on the window. No rush needed as the sealer does not harden.
After you get the body cleaned up and fix any rust if you can find you are ready to put the string in the channel like he shows but no sealer in there.
With your helper you sit the bottom edge of the rubber over the bottom edge in the window opening. You can put some sealer along the bottom before putting it in place. Small bead is all you need inside the rubber channel that fits over body.
When you are looking at window install tools the only metal one you might want is a hook to work the corners with. I use a woodruff key puller to pull just the corners in as someone pushes from outside.
Pull the string and push the window in. No rush just go slow and if the rubber gets hung on flange use your hook tool to flip it over. Once you get it all pulled in go around the outside and push and massage the rubber into place.
Now with your helper take the sealer and lift up the rubber where it is on the metal and put a small amount around the entire frame. You do not want gobs of sealer just enough to fill in any small gaps.
Depending on how tight your car is you can actually do an air check with soapy water. Put air hose inside the car with everything closed up you can and let it blow in the car. squirt some soapy water around the gasket and look for bubbles. If your car is a rust bucket do not even try if nice and tight should work. That is how I found the roof rail leak on my car when brand new.
With the trim off you can polish it if you want. Now go around the opening and every place there is a clip put a small piece of masking tape so you will know here they are. Install the trim should not ever use a rubber hammer should snap right on with finger pressure only. The bottom trim just goes on with screws. You should have checked and cleaned all your clips while the window was out.
I would expect one tube of sealer would be plenty he said three which is crazy. Pic is my 73 showing the tape marking where the clips are.