I did two drift dives in Boynton Beach, FL without the cert and I didn't die.
Joking aside, it's simply a matter of descend, drift along above all of the pretty fish and ascend. Someone in the group has to carry a rope tied to the float. Usually one of the experienced drift divers will do that. I simply learned by watching them. Everything else is basic scuba ... buoyancy control, proper descent and ascent procedures, proper weighting, etc. Beyond the basics of diving there really isn't much to it.
However, if you really want to get the cert, be sure and take your Boat Diver certification first.