Before running dns-proxy-tor you have to add:

  ControlPort 9051

in Tor's configuration file (usually: %%PREFIX%%/etc/tor/torrc).

By default dns-proxy-tor binds to port 5353,
you can use PF to make sure DNS requests get there:

   # Example taken from %%DOCSDIR%%/filter-examples
   # redirect dns traffic from both into the dns proxy
   rdr pass on { lo1 $int_if } inet proto udp to port domain \
     -> 127.0.0.1 port $dns_proxy
   # reroute loopback dns queries
   pass out quick on lo0 route-to lo1 inet proto udp to port domain keep state
   # skip all other loopback traffic
   pass quick on lo0 keep state
   # reroute locally generated dns trying to leave on the external interface
   pass out on $ext_if route-to lo1 inet proto udp to port domain keep state

Add:

   cloned_interfaces="lo1"
   ifconfig_lo1="127.0.0.2 up"

to /etc/rc.conf to create and configure lo1 on boot, add

   dns_proxy_tor_enable="YES"

to start dns-proxy-tor on boot as well. If you want dns-proxy-tor
to bind to the standard port 53, additionally use:

   dns_proxy_tor_start_privileged="YES"
   dns_proxy_tor_bind_port="53"

Have a look at %%PREFIX%%/etc/rc.d/dns-proxy-tor
to see the other optional variables you can use.

dns-proxy-tor's README, LICENSE and changelog were copied to
%%DOCSDIR%%, note that they also contain
information about trans-proxy-tor which has its own port.

Run:

   perldoc dns-proxy-tor

to see how to use dns-proxy-tor without the rc file.