Happy to advise, I have 15 years glass experience.

First, use your new gaskets. old gaskets are stiff and shrunken, only held in the "open" position by the glass that is in them.

Examine the new gaskets. In most cases, they are simple gaskets with a single lip. Sometimes there is a second thinner flap on the inside face. You must tuck the 2nd lip under the outer before inserting the pull rope. Be sure which side faces out.

Apply the gasket to the glass. Make sure the out side is facing out. Make sure the seam is centered at the bottom, hard thing to do since you need to start by inserting the glass at each corner.

Install the rope. Get 3 feet longer than you need, about 1/4in nylon braid. Start at the center of the bottom and tuck the rope into the gasket, and end at the center with the ends crossed. If the gasket has double lips, it is time to tease the 2nd lip out.

Lubrication. Silicone spray is the installers choice, but a very soapy soap/water solution can do. Lube the gasket, lube the pinchweld [lip the gasket fits to]

Get a friend. A professional can solo it, but you shouldnt try.

Place the window in the opening, and do not try to slide the bottom on in advance, just lay it in the hole. Have your friend put gentle downward force at the center bottom while resting a hand at the center top. As your start to pull both ropes, the glasss and gasket may want to rise out of the car. allow it to happen slightly at the bottom of the glass, but not at the top.

Once you have pulled the crossed lines inside, pick which direction to go. Pull the line at an angle that the rope doesnt cut the rubber, and move on around. If the inner lip doesnt want to stay wrapped aound the pinchweld, a few light slaps might be needed there.

REMOVE ANY RINGS!

When you have pulled the rope completely around, step out and have a look. Are there any areas where the exterior lip looks pulled under. Ease them out with a dull, slender hook shaped tool as you gently slap it in {Mac tools has the best hook, just dull it!} Add more lube if need be.

Slapping the glass....the glass is stronger than you think, but that doesnt mean get ham-handed, so be careful.

Still doesnt want to seat? Sometimes you have to seat the inner lip by pulling it onto the pinchweld from the inside.



Or, look for an installer on the way out of the glass shop, and make them an offer. More often than not, they will take it.