Remove top engine cover
10mm (mounting torque - 6-10 Nm)
Cables have different length however I suggest to do one at a time (just in case) unless you have to locate faulty coil first.
To do so you will have to remove all of the bolts holding coils and pull out one at a time while engine is running. Hear and observe reaction of your engine and when you pull the one which will not affect engine - that the faulty one. When you pull them out you will also hear typical sparking noise. PLEASE NOTE if you remove plug one by one you will not find the faulty one as it is twin spark engine and sparks are on 2 cylinders at the same time (coils work in pairs)
After removing holding bolts push the little lever and pull the cable plug back
check for rust
Check if the coil is in the ignition coil if not it stayed on the top of the spark plug. It has to be removed.
I suggest to buy (even used) a Denso ignition coils.
They are two different "stories" :
Denso vs
Sagem
Denso is about 30g heavier. It has more good "stuff" in it than the other ignition coils.
Now it is time for plugs; I had Bosch before however car "likes" much more Eyquem. In fact they are much cheaper (2-3eu) than Bosch (5+eu), so I don't really mind.
Tightening torque is 25-30Nm.
thanks