Remove the seat and turn it upside down.
Loosen the special screws (4), turn the plates (5) and open the seat cover (2) lateral sides to slide it out.

Removal of the seat
Reassembly of the seatRemoving outer components
Note
The following removal operations are required in order to renew and/or
clean the crankcase halves. If the original
crankcase halves are to be reused, then the removal of these components is not
essential.
Unscrew the screw (17) and remove the oil breather valve (1) with the o-rings
...
The immobilizer system
For additional antitheft protection, the motorcycle is
equipped with an immobilizer, an electronic system that
locks the engine automatically whenever the ignition switch
is turned off.
The grip of each ignition key contains an electronic device
that modulates the output signal from a special ...
Refitting the cylinder head assemblies
Warning
To prevent oil leaks past the contact area between cylinders and
crankcase, each time the head is removed, cylinder and
piston must be removed as well to clean the mating faces of crankcase and
cylinder and restore the spoiled gaskets and
o-rings and apply again liquid sealant (sect. ...