It's not hard, you just need to create a .conf file for the wallet (doomcoin.conf in this case) and put it in the right place (for Windows and Doomcoin it will be inside C:\users\\AppData\Roaming\Doomcoin), mine looks like this:

listen=1
daemon=1
server=1
rpcuser=
rpcpassword=
rpcallowip=192.168.*.*
rpcallowip=x.x.x.x
rpcport=9322
rpcconnect=127.0.0.1
maxconnections=100
rpcthreads=10

With rpcallowip commands you specify what mining rigs can connect to your wallet, in my case I allowed access from all machines in my home network and the 2nd rpcallowip command specifies a remote IP-address (hidden with x.x.x.x in the example above) of another mining rig of mine that is outside of my local network. After that you restart the wallet and that's it, now you can mine the same way you do when connecting to pools, just change the address and credentials in your miners' .bat/conf files so that they point to the machine that runs the wallet (your wallet is "your pool" now). When mining over a local network, the address will look something like -o 192.168.11.25:9322 (ip address of the machine running the wallet), -u will be what you called your rpcuser and -p will be your rpcpassword.