Do you have X Window installed on that machine or is it a server with console-only? If it's console-only you need to find an editor you like (possibilities present in every distro: vim, emacs, pico, joe, editor build in into Midnight Commander (to run it: mc)).
Now you need to find 'named.conf' (example in the HOWTO: http://tldp.org/HOWTO/DNS-HOWTO-7.html#ss7.1
). Example from my system:
mara@ruterek:~$ locate named.conf
So the file is in /etc/bind/named.conf (in your system it may be in a different palace). Replace the one or edit it. THe place for zone files can be found in a similar fragment:
So, in my system, the zone files are in /etc/bind.