You can buy a repair kit from B&O,that provides enough of the correct tape to do several repairs.It's special thin tape and very strong,but you need patience to get it right.You need to clean all the original tape and glue residue from the glass and the plastic holder,to ensure that the glass sits evenly.A glue remover will work,but don't scrape the old glue off with a metal tool,as it will scratch the paint off! Use plastic,a credit card is ideal,and I had several I could'nt use anymore for their original purpose(another story!)
Regards,
Nick