How can I stop an old CRON job trying to run?

[#1]

Now that we no longer have shell access to the CGI servers, how can I remove an old job which is just sending me an error message once a week as the script that it ran no longer exists?
Cheers,
Stuart

[#2]

Raise a ticket with details of the cron job to be deleted. Plusnet will delete it for you.
David