[68 TT]

No quick fix. You need to pull the door panel off to gain access to the regulator assembly and the offending parts. You will probably have crud accumulated in the track on the glass and the track on the door shell you can't see that is facing outward that the regulator tracks in but also hardened grease chunks that could be limiting travel and most likely the rollers are crusted up with rust from sitting as well.

I have tried doing this without removing the regulator but freeing up the rusted rollers is next to impossible without being able to get to the side that is shielded by the guide track and getting the crud out from under the rollers is just as tough with them in the way. You might be able to just grease the snot out of the track and make it work with rollers that don't roll but after doing all the work of removing the arm rest, window & door handle and door panel fasteners it is a shame not to do the job properly and spend a few more minutes taking the window regulator out.

The four screws holding the regulator to the door shell are usually really tight and are a #3 Phillips head screw. Hit them with WD40 before you start in on them. I found a 1/4" drive socket with a #3 Phillips bit in it on a 6" extension with a 1/4" ratchet work much better than a screw driver at breaking them loose. You can push in on it harder so it is less likely to slip out of the screw and you have more leverage to turn it also. If you still can't get one loose with the Phillips drive the heads are tall enough to get a pair of vice grip pliers on them so you can break them loose that way as well. Once you break them loose hit them again with the WD40 so it can get to the threads for sure. It really sucks to break off a rusted fastener after you get it started to come out of the part. Don't ask how I know that

You need to take the screws out of the wing window at the top of the door frame jamb and at the base of the door panel so it can tilt out of the way of the regulator mechanism just enough for you to remove it from the door. It almost makes it out of the door shell without doing this but not quite.

Hose down the rollers with WD40 or your penetrating oil of choice then blow them out as you gently try to get them to rotate freely. It doesn't take much rust in the axle area to keep them from rolling. Don't use anything with teeth on them to try to twist the rollers like slip joint pliers as the rollers are very soft and will get damaged. I found the inside of my wiring lineman's pliers have a nice round clearance notch in them that fits just right around the rollers and they give just enough grip to let you get some leverage on the roller to help break the rust up and free the roller from the shaft.

I found Home Depot has a pack of 100 zinc plated 1/4-20 x 1/2" long pan head Phillips screws for under $7 and 50 packs of plated versions of the outside serrated star washers that look like what is on the doors for $1.50 so I have been using them in place of the old fasteners when I take out the old ones if they are rusted or get damaged on removal. Sometimes on the same door a few of the originals are still looking great and some look like they were on the Titanic. Maybe different plating as they came from GM or just pure luck of exposure to water but it doesn't seem to matter as to how the threads are. I have had ugly ones come out fine and nice looking ones require extreme measures for removal.

Chase all the threads in the regulator, door panel mount points and arm rest mounts with a 1/4-20 tap before you reassemble everything to clean out the crust, blow out the debris then push some silver grade anti-seize compound into the holes and for good measure a dab onto the fasteners as well upon reassembly so nothing ever gets stuck again in the future.

Hope this helps.