you'll need to cure the rock again unless you want your tank recycling. Put it in a rubbermaid with a powerhead for circulation and a skimmer if you have one. Test the water...you'll probably see some ammonia b/c of the die-off. Change the water periodically until your ammonia tests are at 0, and nitrites at 0. Its hard to tell how long it will take, that really depends on how much die-off you encounter.
If you dont care about causing delaying your tank cycle and dont have any fish or inverts yet you could just go ahead and let the rock cure in there.
HTH,
Mark