It depends on the adhesive. Usually a glue or double sided tape.
If its glue, you may try some acetone (get a cue-tip and gently work some behind the tab. That may start to soften and dissolve it. You can tell if it softens by tryingy to slide a thin piece of metal or knife blade between the tab and the glass. HOWEVER, only use this as a test to see if the glue is softening. DO NOT PRY, TWIST or PULL against the two surfaces. Be patient and let the acetone work slowly.
You can also try some heat from a heat gun to see it the glue softens. Again, go slow.
If its double sided tape, you can get some dental floss or very thin metal leader fishing line. Place it between the tab and glass and work it back and forth, almost like a sawing motion.
Again, DO NOT PRY, TWIST or PULL the pieces apart. Go slow and be patient.