Hi the battery is under the right hand side panel, that's just one screw and two pop clips that pull off, The seat is held on by two 10mm bolts under the seat up under the mud guard, usually covered in mud, Brian does some nice bolts to replace these!
There is a service manual that you can download for the blue and this will give you a start, maybe someone knows of one for your OE.....
Cheers just got to that point Was covered in mud as you predicted lol. Was surprised to find the seat bolted down.
Am taking off a previously fitted sat nav and fitting one given to me with the bike. So petrol tank lifted and given the air filter a dust. Also made the chain tighter