I recently did this on my 1989 300E. I've also got leather power seats.
First, you have to remove the two Philips screws on the bottom of the panel. Then remove then panel. I'll try to explain this but it's hard to visualize...
The panel does not actually *slide* off. There are three metal clips on each side that hold the panel to the chair. One at the bottom, one in the middle and one at the top of each side of the panel. The clips are held in place by pressure - i.e. no direct holes or fittings, they just snap into place. There is a groove in the chair assembly that the panel is fitted into on each side. Starting at the bottom corner of the panel, use a flat screwdriver and gently pry the panel off the chair (the crease where the panel meets the side of the chair). It may take a little bit of force, but just go smoothly. You'll see the panel coming out from the chair and the first clip should pop off. Once you get the first clip off, the rest are easy. Basically, the edges of the panel tuck into the chair assembly and are held in place by the clips through tension.
Once you've fixed the map holders (I glued mine with super-glue and re-tensioned the mesh), it's easy to re-assemble the panel. One tip I got from this board which was helpful was to have someone sit in the chair when you are re-installing the panel. This provides some slack and makes it easier to install.
2007 E550 4Matic - 61,000 Km - Iridium Silver, black leather, Sport package, Premium 2 package
2007 GL450 4Matic - 62,000 Km - Obsidian Black Metallic, black leather, all options
1998 E430 - sold
1989 300E - 333,000 Km - sold
1977 280E - sold
1971 250 - retired
"And a frign hat. They gave me a hat at the annual benefits meeting. I said. how does this benefit me. I dont have anything from the company.. So they gave me a hat." - TheDon