There are two types of Corny's; ball lock and pin lock. The pin locks are pretty easy to identify by the two small pins on the connectors:
You will need to go to buy one gas, and one beer connector appropriate for the type of corny you have. You will need to replace the existing connectors on the kegerator with the connectors you just purchased. When you open the lid on the corny, the gas line will not have the pick up tube connected to it. You will also need a couple of hose clamps to tighten the new fittings to the lines, you may also want to consider buying about 10' of "beer" line so that you can balance the system depending upon the volume of co2 you run, and just for sanitation purposes, if it was a used kegerator.