'99 1500 OBS -- rear window coming loose

[SierraClassic]

On a rainy day this weekend water started draining into the rear of the cab at the top corner of the rear window (slider in a 3-door extended cab). At that corner the rear window is coming loose, but it's not just the glass. It looks like the whole assembly (rubber, glass, frame and all) is coming loose from the cab (?). Anybody know what's involved to fix this, and does this sound like a job for the dealer or maybe a glass shop (thinking about having the front windshield replaced anyway)?

 

Thanks,

Stephen

[SierraClassic]

Problem solved. My truck has a new windshield and the rear window is glued back on.