Is the glass skin fractured, or just dented?
What I have normally done for things like that is to take a very thin straight pin or sharp #11 X-Acto blade and use it to pull up the skin where it has been pushed in. If the skin is not broken, you can poke holes using the pin. These holes will come in handy... just hang on.
Using the pin to hold the skin in position, carefully wick thin CA into the crack/holes using the applicator tube (if available). Once the CA has kicked off, move to the next section and continue until the area is stabilized. If the skin was badly torn, you may add some light glass (25g/m^2 or .075oz/yd^2) over the area. Otherwise, just lightly sand and then apply spot putty to blend the area in. I use "white putty" from Squadron. (
http://www.squadron.com/ItemDetails.asp?item=SQ9060 )
good luck,
-David