I think it is almost impossible to requeen a nuc (or hive) with the existing queen in place. One must find and remove her...or kill her. On the other hand, if one starts with a queenless nuc or package it is easy to introduce a new queen. Remove the cork from the candy end of the cage, put a hole in the candy with a long nail. (Don't injure the queen doing this.) Put the cage candy end up in between two frames. In 72 hours check and remove the cage. If the queen is still there, lift the wire and let her go on top of the frames. You do not need to remove any workers from the queen cage. Best of luck, Lloyd Lloyd Spear, Owner of Ross Rounds, manufacturer of comb honey equipment for beekeepers and Sundance pollen traps. http://www.rossrounds.com [log in to unmask]