Battery box and/or airbox are fairly easy to remove and will give best access.
You might need more detail on Battery Tray removal (from manual):-
Unclip plastic cover, disconnect battery terminals, unclamp battery. To remove the battery tray, depress 2 retaining clips & slide ECU up a bit from the tray. Slide out locking catches on ECU wiring plugs and disconnect them. Unclip the wiring loom from battery tray, then slide ECU up & out tray. Remove air filter housing.........then undo the 3 bolts holding the battery tray, unclip the positive battery lead from underside of the tray & lift it away.
Just be careful with the ECU & connectors (expensive!), as long as battery is disconnected first there should be no problems with it but on refitting you may need to initialise the electric windows (or sunroof if fitted.) Don't connect battery until all ECU connectors have been re-connected.
Windows:- close the door, raise the window & hold the switch in the up position for at least 5 seconds - initialisation is complete ECU will have relearned the window reference points.
Sunroof:- hold switch in fully tilted position for 20 seconds.