srrichie,
just strip your sketch from all the calls to ethernetUDP and replace it with the appropriate parts of WifiUDP calls in the example I posted above in this thread.
so
EthernetUDP Udp;
becomes
WiFiUDP Udp;
etc...
and if something doesn't work, post your complete code then we can take a look at it and quickly see any mistakes.
I would also suggest to always compile with verbose output. You can switch verbose output on in Arduino > Preferences