ALL XJ windshields are "glued" in. They never made them with a rubber gasket like they did on the CJs. Since it was never an option, it would be impossible to do as there is not a gasket made for it. That being said, w/s replacement is not something that can usually be done correctly by someone without experience. Consider this: an average price for a w/s from a junk yard is $75.00, that is for a used w/s with NO warranty. To install it right you need to buy 2 tubes of urethane from a glass shop for $5-6 each. Then if you break it whlie transporting or installing, you're out $75.00, and maybe your jeep is sitting there for a day or two while you try to locate another one and hope that they don't break it getting it out and hoping that you don't break this one too. Let's say that you get it in ok but it leaks (highly probable for a novice) on your stereo, cb, or other expensive equipment. That's up to you to find and remedy. Now you could take your used w/s to a shop and they will install it for around $50-$60 but will offer no warrany as it is used and if they break it putting it in....you're screwed. Now consider the benefits of buying a new one: if you call around a bit you can most likely get a new one for $150.00-$200.00 range. Call all the shops in your area as prices can vary widely and shops tend to be competitve, if you mention a price from someone else they will usually try to beat it. Ask about their warranty. Any reputable shop has a lifetime warranty against leaks and manufacturers defects, some even offer free lifetime chip repair. Now if they screw something up during the install, it''s their problem.
I'm not trying to tell you what to do, it's just that sometimes what seems to be a cheaper way, doesn't always turn out that way. When I had my shop there were multiple time that someone would bring in a used w/s and by the time all was said and done they had only saved $30-$40 over buying a new one.
Good luck!