You will have to use a battery charger or other source of 12V high current if you cannot get access to the screws that holds the seats.
Once the seats have been elevated, they are about 50 kgs each and it will take two persons to get them out of the passenger compartment
without risking the leather which is extra delicate if the seats are ventillated.
Once the seats have been elevated, there must be no 12V present/ignition in any active position since there are SRS air bags in the seats.
If the SRS chain is broken while ignition is on, there will be an error code set which requires a diagnostic tool to reset.
Make sure all connectors are disengaged before trying to lift out the seats.
(At least) CL "C215" uses pneumatic lumbar support, there are stiff air hoses that connects to the hydraulic pump
in the luggage compartment. There is a Y-joint underneath the carbet that is prone to brake. Possibly the center console will
have to be taken out as well in order to gain access. If the Y-joint is cracked the seats will have to be taken out once again to fix it
so be careful.