got it from the net, i hope it would help

Prepare the materials:

Spark Plug Socket wrench
Sandpaper #1500 for Spark Plug
Thin tipped knife or pointed tool.
Bristle Brush

Make sure your engine has rested after an hour or so, to avoid burns.
The Spark Plug is hot after using your car, let it cool first.

Pull the Spark Plug Collar.
Using the Spark Plug Wrench, twist counter clockwise to loosen the spark plug.


Spark Plug, up close & personal.
Using a pointed tool, scrape off carbon residues on the plug’s tip to reveal the probe.


Using a Sandpaper #1500, sand the probe gap.
Check the gap if a flat screw driver’s tip can fit in between.
Hammer it down to close in the gap or separate if it is too close.
Bristle brush or blow the dust & dirt off the spark plug.

Return and screw it.
Tighten it using a Spark Plug Wrench, Not too tight!
A ¼ arch will do the trick.

Snap the high tension wire collar to the plug’s end.

http://www.expertvillage.com/video/6...s-cleaning.htm