Mercedes-Benz CLK Coupe Operator's Manual page 285

Instruments
Operation
and controls
Electronic main key
Insert mechanical key (4) in side opening (5) to open
latch. Press briefly (do not use mechanical key as lever)
to release battery compartment.
Remove mechanical key from side opening.
Carefully remove battery compartment in direction of
arrow (6).
Instrument
Driving
cluster display
5
4
6
P80.35-2025-26
Practical hints Car care
282
Change batteries (7), inserting new ones under contact
spring (8) with plus (+) side facing up.
Return battery compartment into housing until locked
in place and slide mechanical key back into electronic
main key.
Technical
Index
data
7
8
P80.35-2027-26