These are the directions I followed from Reefcentral.com:
I spent almost all day Sunday April 4th making fresh RO/DI water to be mixed with my D-D H2Ocean salt mix. It takes approximately 72 minutes for a 5 gallon bucket of RO/DI water. So about 7-8 hours of making water, most of it poured directly into the new tank. I had about 10 gallons of freshly made saltwater from the night before already poured into a 18 gallon Sterilite tub with a old 100W heater and 4 (160-247gph) powerheads.
I still had water that I drained from my old tank so I poured and filled (2) 5 gallon buckets. I got a new bristle brush and scrubbed every nook and cranny on each live rock removing detritus, algae and any other crud that it may have accumulated the past year. I then dipped and swished it around several times in the second bucket before moving it into the tubs in my garage.
Here's some pics of my first week of "cooking" live rock:
Week 1: Fiji Live Rock on the left after one week, fresh saltwater on the right.
Week 1: Lots of nasty crud on the bottom after letting it sit there for a week
Week 1: Right after swishing the live rock moving the rocks to the 2nd tub
Week 1: Old dirty water on the left, Live rock in the new saltwater on the right
Week 1: The next day after the dirty cloudy water settled, crud that "automatically" came out of my live rock.. which looked cleaned on day 1 of cooking.
More updates to come...