New glo plugs fitting ??

I have a feeling that after 5 years it's time for new glo plugs. Never
fitted them before ? Are they simply like sparking plugs or more of a
problem ?
I assume that I simply undo the terminal at the top and then torque in the
new ones; however do I have to disconnect the battery when doinh this ? I'd
rather not if possible.

--


" ..... it is the provenence of knowledge to speak, and it is the privelage
of wisdom to listen"

(I didn't as the battery had gone
> flat in my multimeter dammit).
>

Only when you need the meter though )