Step 1. Find your engine bay
step 2. disconnect your oil vapour pipe from the rocker cover
step 3. undo the 2 x 10mm bolts from the top of the cambelt cover
step 4. Pull cambelt cover away from rocker cover
step 5. remove spark plug cover (4mm allen key) HT leads and maybe place an old rag on the exhaust manifold to stop oil dripping onto it
step 6. Remove the 4mm allen bolts from the rocker cover. There are 11 to remove and remember which order they go in as some of the bolts are longer than the others!
step 7. The rocker cover maybe a little bit stuck, just give it a tap with a club hammer and it should free up, just pull rocker cover away to reveal this
step 8. Replace the rocker cover gasket (7766412) and spark plug O-rings (7574731)
step 9. Replace cover and tighten the bolts up finger tight. I have used this sequence to tighten the bolts up, i dont know if it is right or wrong, but its the way i have done it. Tighten them up (only enough to nip the gasket) check all the bolts again, then check again afterwards.
step 10. Re-connect your HT leads, oil vapour, cambelt cover and spark plug cover. Start engine and check you have no oil leaks. Job done and should only take about 30 mins