Get a spark plug socket and a ratchet, or a spark plug tool (measure up against new plugs as there are two different sizes)
remove HT leads from plugs
unscrew plugs one by one. If you cant get it out, gently push the HT lead required on and pull the spark up attached to the lead.
fit new plugs, ensuring you dont cross thread or over tighten them
refit leads
test start
