On the left side of the bike above the rear tire you will find a lock assembly where you can insert the ignition key, that is connects to the seat latch. Turn the key and lift up on the back of the seat.
Below is a link where you can see the assy I am referring to
Regret I only got your response sent to me 18h32 and I had already got the problem solved at Halfords by that time for the trip home.
Key slot mentioned was hidden behind Givi luggage box.