you technically can just change out the glass but that would not be a good idea. it would be better just to buy a new one. the vinyl part on my top started to seperate from the glass and i kept trying to glue it back but it looked terrible, i kept having to re-glue it every month or so and it would never glue up evenly.
new ones with the glass cost about $130. if you can go to the junk yard and find one there. that would be best because new ones don't come with the part that you have to bolt down on the bottom. you would need to take it somewhere to have it installed. good luck and sorry about what happened to your stang