First you need to check the material of the tumbler so that the exact method can be suggested. There are different methods to remove glue from different surfaces. For example to remove glue from Acrylic Plastic, Aluminum, Asphalt, Ceramic, Glass/Tile, Cork, Glass, Linoleum etc, you can use dull knife or spatula.
There is also a product WD-40 which can do a trick for you. For both methods, visit the following links for detail.
Glue Removal
WD40
There is also a product WD-40 which can do a trick for you. For both methods, visit the following links for detail.
Glue Removal
WD40
