If you have an already cycled tank:
Put the rock in a bucket/tub
heater and ph
Check for ammonia (should show up in about three days)
If no ammonia is present, you could put it straight into your tank.
If ammonia is present, you will need to cure it.
I have 100Lbs of his rock sitting in my garage right now. I am waiting for the last 50Lbs to come in.