Wrap the above with carrier/plastic bags. Let the engine run!
Spray a cleaner like 'GUNK engine degreaser' then hose down the bay. avoid jetting the rocker cover as it will make it flake
All i do is jack up the drivers side of the car so water can run out from around the plugs. If not after a couple of days you will notice a miss fire from water in the plug holes.
Dunx