Once the visual clarity returned to about 90%, I plugged the vent holes with the small, clear plastic caps provided in the kit. Then, I ran a thick bead of high-quality silicone sealant over the holes and re-sealed the edges of the glass where the original seal had failed.

To fix it without replacing the glass, I had to do three things: let the moisture out, clean the interior glass, and re-seal the unit. I ordered a defogging kit online—a relatively obscure toolset that looked more like something used by a veterinarian than a handyman.