Luckily you can replace just the glass, 3x T25's on each side of the inside rails I believe, then just lift it up and back (onto a towel) and drop in the new one.
Try local auto salvage shops, or local junk yards.
You may have to purchase it as a complete assembly, though I know when I worked at LKQ, when I searched our system for sunroof assemblies, there were more than a few just glass results.
Car-Part.com would be a good resource too.