How do you glue these back on?

The best plastic glue I have found, 3500 psi tensile strength, glues ABS,
High-Strength Acrylic, Plexus 30500, 1.58 oz. Cartridge made by Devcon,
Mcmaster-Carr has it, You need a gun but I use it for a lot of stuff. It glues all metals, ceramics, concrete, wood, never had a failure with it but JB wont glue metal to plastic It has failed every time, sometimes it holds for 6 months but it eventually falls off.

Hmmmm. Wife is a dental assistant, just happen to have a gun and mixing tubes..........