hammer 's are somewhat harty, did it come shiped in or local pickup? if shipped float bag for 15min or so, if local can kind of ship this step. i use a turkey baster and add water to the bag. when the bag get somewhat full, i pure or take some out and down the drain. adding the water slowly for about 15 min. after that i remove the coral and place in take low and go from there. the left over water in the bag can be dump down the drain.
If it's not too late turn it upside down while it is still in the bag before pulling it our of the water. The skeleton is VERY sharp and can/will damage some of the tentacles with thier weight when out of the water.