Soak them in oxyclean and hot water for anywhere from a few hours to overnight and then rinse thoroughly. If there is any "scale" left on the bottles after soak them in a diluted weak acid, like water and lemonjuice or vinegar, or dilluted starsan.
A hot water soak in oxyclean. Some brands will slide right off once the glue melts. Other's you'll have to take a kitchen sponge to it (the kind with the ruff side.)