Semyas -
It really depends on how deep the glue has eaten through. Definately do the sanding procedure, I start with 600 wet/dry, wet of course ;) , and work up to finer grades as required. As the windshield will now be cloudy, dip it in future floor wax, and leave it alone for a few days. Note, in theory, even if the glue has eaten (wrinkled) through, you might be able to recreate surfaces, by careful sanding. I've never tried fixinhg anything that bad, but what do you have to loose?
Also, if this is a Revell/Monogram kit, still in production, surprised that no one suggested just going to their website and asking for a replacement part. They're pretty good about that. At least they used to be.
Archer out.