Thanks OO for your very useful information.On the inside rails of the sunroof mounts, there are 4 Hex screws that you can remove and they offer some adjustment for where the glass lands.
Stern Warning Here: The sunroof is held to the moving assembly with a plastic carrier on each side that is then moved by the motor via cables. That piece of plastic is nearing 20 years old for many of these WJs and this is your warning to take very special care of the assembly. Specifically, you should remove the glass by pulling those 4 torx bolts and lifting the glass up from above. Then vacuum, then clean any debris from the tracks to ensure that little piece of plastic on the carrier is not being overly stressed. Lubricate the track and any moving parts with light grease, moving the carrier without the glass installed. Do this about every other year. If you experience super cold environments and ever open the roof during those times, use very light grease.
If that carrier breaks, you are screwed and if it breaks with the roof in the open position, it is very difficult to get the glass to move back to the closed position but it can be done. That carrier breaking is also going to screw you because it is not a replaceable item. It is integrated to the entire assembly and under the headliner. The dealer does not have replacement carrier or the entire assembly anymore. The junkyard is your only hope, but those are also 20+ years old and pulling those things down from under the headliner is no picnic. It's not tough and does not require any special tools but it takes a very long time to do and wrestling with that headliner out and back in afterwards is a huge PIA.
So run it back and forth a few times if you want but best to clean the tracks, adjust the glass position as best you can and try to ensure you are not screwed by this bad assembly design.