Q. How does one kasher a glass top stove for Pesach? What if the glass is scratched or was damaged or has aluminum (foil paper) stains imbedded into it?

A. The glass-ceramic top should be totally clean (use the recommended commercial ceramic stove top cleaners) and not be used for twenty four hours.Turn on the burners to highest setting and live them on red hot for forty five minutes.
Since only the area directly over the burners becomes hot, the rest of the surface should be covered with preferably a double layer of heavy duty aluminum foil. Take care not to place foil over the heated area, as this may crack or harm the counter top.
If indeed the aluminum foil melted into the top’s ceramic material and it cannot be removed or if there are cracks in the ceramic/glass top, Horav Shlomo Miller’s Shlit”a opinion is that it can still be kashered and is not considered a rusted utensil that cannot be kashered (Shulchan Aruch O.H. 451: 3)

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a