OS: Debian 6 Server Version

I have different logfiles which are filling up:

user@server:/var/log$ ls -lahS | head
total 427G
-rw-r--r-- 1 root root 267G Nov 2 17:29 bandwidth
-rw-r----- 1 root adm 44G Nov 2 17:29 kern.log
-rw-r----- 1 root adm 27G Nov 2 17:29 debug
-rw-r----- 1 root adm 23G Oct 27 06:33 kern.log.1
-rw-r----- 1 root adm 17G Nov 2 17:29 messages
-rw-r----- 1 root adm 14G Oct 27 06:33 debug.1
-rw-r----- 1 root adm 12G Nov 2 17:29 syslog
-rw-r----- 1 root adm 12G Nov 1 06:26 syslog.1
-rw-r----- 1 root adm 9.0G Oct 27 06:33 messages.1

So I looked up the file /etc/iptables.up.rules which had those lines in it:

-A FORWARD -o eth0 -j LOG --log-level 7 --log-prefix BANDWIDTH_OUT:
-A FORWARD -i eth0 -j LOG --log-level 7 --log-prefix BANDWIDTH_IN:
-A OUTPUT -o eth0 -j LOG --log-level 7 --log-prefix BANDWIDTH_OUT:
-A INPUT -i eth0 -j LOG --log-level 7 --log-prefix BANDWIDTH_IN:

So deleting those lines will solve my problem.
But how would I edit those lines without losing their functionality?