Use a piece of thin stiff wire like piano wire or windshield removal wire to get old glass off. Remove any excess adhesive but down to bear cab frame, leave residue of old adhesive. This will act as primer for the new. If there is any bear (unpainted metal), prime and repaint those areas. If the window has a painted edge, painted side goes towards the cab. Clean window with good class cleaner and apply primer to the window and areas on cab without adhesive residue. Let primer dry, about 5 minutes. Apply 1/4" bead of adhesive around cab frame. Install the window pushing in to compress the adhesive, then tape it in place. Let set a minimum of 2 hours, more depending on temperature and humidity.