Disabling a service in inetd is simple: Just comment out the line in /etc/inetd.conf. You probably don't want to remove the line entirely, just in case you need to reference it later. For example, some system administrators prefer to disable telnet for security reasons (since the connection is entirely cleartext):

# vi /etc/inetd.conf
[comment out undesired line]

# grep ^.telnet /etc/inetd.conf
#telnet  stream  tcp     nowait  root    /usr/sbin/in.telnetd