The rear antiswaybar stays in place, the front antiswaybar comes out. I'd go for a Currie Antirock over that Rocklock BS though. The Rocklock is nothing but a very expensive disconnect for the front antiswaybars, it does nothing to help with offroading than simply disconnecting them does.
Currie's Antirock, for about the same $$$, actually helps offroad by helping to balance the front and rear suspensions so they work together instead of fighting each other like when the front antiswaybar is completely disconnected as the Rocklock does.
Either save your $$$ and get a JKS Quick Disconnect for 1/3 the $$$ that does the same thing the Rocklock does but takes 1 minute longer to use, or spend the same $$$ and get something that actually does something worthwhile... the Currie Antirock you can see at Currie Enterprises Antirock System
Builders and competitors run the Antirock because it actually helps. In fact, John Currie won the U.S. national rockcrawling championship using a pair of Antirocks for the front and rear. I've had one on both of my Wrangler TJs and I would never run anything else.