You just have to remove the glovebox complete and
remove the access door on the heater box.
There are 2 paper filters slid in like cassettes.
Replacing them is the correct proceedure.

__________________
Dr.Diesel -
Shop Foreman
Master Guild Mercedes-Benz Technician.

Think the dealer is expensive? Do you know how much it costs to train a dealer tech? Or buy the required MB special tools to have on hand?