Take all four plugs out of the engine as well as it makes it a lot easier to turn the engine over by hand. Put a rag round the valve you are working on to prevent the collet dissappearing down an oil way.

Tool is about £10 from and decent MotorFactors. Think mine is a Sykes Picovant and cost me £7 three years ago. Draper one is a bit pants and bent halfway through doing the job