I’m trying to rig a face and so I have geometry with weight distributed across 3 or even 4 joints. Basically I want to take all of the weight off of one joint and transfer it to another without disturbing any other joints that also have weight on those vertices.
Go in the Rigging layout or open Character > Manager > Weight Manager. In the Joints tab, select the source joint, then in the Commands tab, hit Copy, then Zero. Then select the destination joint and hit Replace or Merge.