the plugs r easy to get to... just take the cover and the coils off with an 8 mm socket and the plugs are a 10mm spark plug socket. Make sure you pull the tubes off the plugs carefully cos sometimes they r stuck slightly a little wd40 works a treat. If the plugs are whiteish it indicates a weak air/petrol mix where as black indicates a rich mix. If the plug electrodes r oily that indicates a more serious prob.
its a simple job just dont over tight anything when u come to put it back and remember which lead/coil goes where.
Hope this helps