Position seal (18) in tank cap (10) as shown and reassemble following the removal procedure in the reverse sequence.

In particular tighten the screws (17) to a torque of 3 nm +/- 10% (sect. 3 - 3, Frame torque settings).

Removal of the fuel tank filler cap
Replacing the tank flange and fuel sensorReassembly of the crankcase halves
The crankcase halves must be in good condition and perfectly clean. The
mating surfaces must be perfectly flat and free
from burrs.
Overhauling the alternator-side crankcase half
The following parts must be present on the internal side of the crankcase
half:
Gearbox secondary shaft bearin ...
Removal of the throttle twistgrip
Peel back the rubber sleeve (a) protecting the throttle control cables.
Undo the screws (b) of the throttle grip (6) and open the command.
Disconnect the throttle grip cables (10) by unhooking the cable ends (c) from
their seats.
Remove the throttle twistgrip (6) from the handlebar.
...
Refitting the gear selector lever
Position the gearbox drum selector fork in the centre of the gear rollers.
Position the gear selector lever (21) together with control shaft, spring and
plate into the chain-side crankcase half.
Insert the screws (18) and (20) with the spacer (19).
Temporarily fit gear change lever (or a ...