[header] How to change spark plugs in a renault clio mk3 [title] Park up your car on level ground and wait for your engine to cool down. [step] If the engine is already cool you can begin work on your car. [title] Disconnect your car battery. 
[step] Make sure your battery is disconnected before performing any work on your electrical system. You don't want a shock or even worse to fry your on board computer because of a shock.