I dropped A bead down the ac vent. How do I get it out? It rattles when the ac

Only thing I can offer is - Good luck !

Other than disassembly of the dash and the plenum, I don't know of any "easy" way. You could access the cabin air filter and see if it made it's way to that area. Doubtful though. Some kind of flexible rod with a magnet if the bead is metal and able to be picked up by a magnet... But yeah...not good!