Make sure you have a tubular spanner or proper spark plug spanner of the right size
Make sure you have a set of feeler gauges and understand how to use them
Check the manual and buy the correct number of the correct type of spark plug.
Check the manual and make sure the spark plugs are gapped properly (do use a feeler gauge and chceck one of the innumerable giuides on line of in doubt)
Take off plug lead
Clean and Blow away any debris found the plug, so it doesn't fall in the engine when you remove the plug
Carefully unscrew the spark plug (Using a tubular spanner or proper spark plug spanner of the right size and being VERY careful not to tilt the spanner and snap the ceramic)
Carefully screw in the new plug and just nip it up tight (no need the be brutish)
Replace lead
Replace any covers
X, March 2015
