The plugs on on the side nearest the bulk head.
Don't attempt this job with a hot engine, allow it to cool a while.
Remove the front part of the airbox and filter the a couple of bolts will allow the airbox to be lifted from the throttle body.
The plug caps are quite tightly fitting and require a little tugging to get off. Pull the caps, not the leads as you might pull the lead from the cap.
Do one plug at a time in case you mix up the leads.
A ratchet, extension and plug socket will reach each plug, though you may have to shove a few bits and pieces out the way to get at the inner two plugs.
To get the new plug in, slip a couple of inches of hose/tubing over the (insulated) end of the plug.
This will help you hold it in the recess and start screwing it in straight by hand.
The plugs screw into a alloy cylinder head and it's not unheard of to cross thread them and ruin the threads in the cylinder head.
They don't need lots of torque to tighten the plugs, screw them in until the stop, then a firm "nip" with the spanner is enough.
DO NOT swing on them with all your might with a long handled ratchet!
A firm push down of the caps on to the plugs will see them seated.
I think there is a small hose on the under side of the airbox that will need fitting as you line up the 'box to refit.
