The spark plugs are screwed on the sides of the cylinder heads, on the side of the exhaust ports. Common tools required for spark plug replacement are a spark plug socket adapted to a ratchet, different extension and last but not the least a gap checkers which has the responsibility to check the gaps of the replaced spark plugs. There are special tools for the removal of plug wires from the wire boots but this is not compulsory, the torque wrench should only be used to tighten the new plugs into place. For this job it is useful to buy new plugs beforehand, install them on the correct gap, and install them one at a time for the correct plug type for the engine. New spark plug should not be fitted without prior confirming that they are free from any defects and that the gap has been set properly and this should be done after the engine has cooled off and all the plugs have been removed. The gap is measured by placing the correct thickness of gauge between the electrodes at the tip of the plug; if the gap should be altered, it is done by bending the side electrode gently without distorting the porcelain insulator. Remove the front wheel lug nuts and then lift the front of the car up using jackstands and then remove the wheels and inner fender splash guards as to access the rear plugs easily. When it's cold restart the engine and after the engine is cold, disconnect the spark plug wire from one plug pulling only on the boot On the spark plug hole blow with compressed air. Insert the spark plug socket over the plug and unscrew it anti-clockwise, if necessary, use an extension. Consequently, the comparison of the old spark plug with the chart document the running condition of the engine, while a thin layer of the anti-seize compound must be applied to the threads of the new plugs. Screw a new plug into the hole until it can't be turned any further by hand, then tighten it up as far as possible using a torque wrench or ratchet; fit a short length of rubber hose onto the coupling to prevent cross-threading. Last of all, tighten the plug wire on the new spark plug with twisting motion and carry on the same for the rest of the spark plugs but connect them one by one to avoid confusion between plug wires and correct position, if connected wrong it may cause misfiring of the engine.