Cleaning over lap in shower doors - suggestion
I can't post on the OP's original post because of an ad that won't go away :-(
You should be able to slide the left door to the right and the right side to the left, which would expose the "gray" area.
Or, you can do as I did and take the whole thing out. It really wasn't difficult and over a few days, the paint scraper took care of all the glue gook on the bottom, and gently took most of the silicone off the sides. When I can open the window for ventilation, I'll use some thinner to finish the job. I will NEVER have shower doors again!!!
The instructions are on the Bathrooms forum under "Removing Shower Doors".
Here's the link:
Here is a link that might be useful: Removing Shower Doors