I suggest you go to your local MB dealer, buy the removel keys(I paid $10 for mine), and have them show you how to use them to remove the climate control module. It's very simple. On my '96 C280 the bulb inserts in the bottom of the control module. Yours is probably the same. Remove the bulb, buy replacement at the dealer, install the new bulb and push the module back into place(with the keys removed).

Dan