editing /etc/init.d

[john gennard <joney@clara.co.uk>]

I need to edit a script in /etc/init.d to allow a program, which I
haven't been able to get to run, to log what is happening.

So far I've not touched this area and find the manpage for
'update-rc.d' a little confusing. The script to be edited is linked
to /etc/rc0/  .... /etc/rc6/ (as defaults with runlevels and
sequence code). Do I need to remove all of these links with -f,
so running 'update rc.d -f xxxxxx defaults' ? 
I presume I could run the same command with -n instead of -f
just to have a 'look-see' -but I'm wary of touching something I
don't yet understand. In any event this seems too simple.

Would someone be good enough to advise me.

Thanks,    John.