Installing foglight lens on Audi 100 CS-Q
 

Can anybody give me some suggestion on how to remove the broken glass remains of an old lens in a foglight housing (1992 100 CS Quattro). Both my lens broke, housing and inner parts are good. Small pieces of glass are firmly adhered in the bonding groove around the housing which is where the original fog lense was bonded or glueed in place along the outher edge of the housing. I wonder if any one knows of a trick to remove these peices pf glass, a solvnent which might dissolve the glue that holds them in place (for example). Would appreciate any ideas. Need to install the new lenses but can't do until I clean the groove appropriately...
thanks
Ed