Any advice on changing this switch?

• remove negative battery cable
• carefully remove airbag (torx screws in hole on either side)
• remove steering wheel; undo electrical connections
• replace switch
• remove panel under steering wheel in footwell to gain access to connection
• repeat in reverse

Do a search for "combination switch" and you'll learn more than you ever wanted to know about the procedure.

G'luck and welcome

__________________
-Paul-
'01 E430, Sport 72,000 mi
'98 C280, 126,500 mi

Maybe this will help, there are other articles under the DYI in the "resources" bar at the top of the screen
http://www.peachparts.com/Wikka/W210LooseTurnSignal

Job successfully completed, thanks for the info., especially that this is really called a combination switch. A friend has the T30 bit and an impact wrench, which easily defeated the 10 mm nut! However, this was a fiddly job, one to tackle methodically. Useful to have the front wheels off the ground to rotate the steering wheel to access the Torx screws.