Boil it up in about 2 cups of water, and make sure it's dissolved well. You'll need about 1 1/4 cups for a regular 5 gallon batch.
Pour that into your sanitized bottling bucket, and then rack the beer into it, with the tip of the tubing at the very bottom at an angle, so that the beer enters the bucket at the bottom without splashing, and then "swirls" to mix as it fills.