• 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