how can i edit a "read only" file (/etc/*.conf)

[t0rp3d0]

Hi,

i run Knoppix 3.1 as a network auditing tool.

PROBLEM:
i am not able to launch a #nessus-update-plugins because they are stored on /usr/lib/nessus (read only directory)

i wish to edit /etc/nessus/nessusd.conf and change the line
#plugins_folder

but -again- i found myself with a read only file

Any idea?

Thanks for your support.