Just unvote the witnesses you have (e.g., anarcho-andrei, gmuxx, sircork) and then vote noblewitness. You may rewatch the video as I explain within the rambling two methods of doing this using:
https://steemit.com/~witnesses
The explanation/demonstration is at about 27:00 minutes into the video.
Hope this helps.
got it thanks done!
Good man!