Cover the Kershaw knife blade with masking tape. Tear off small pieces of tape as necessary to tape the blade in between the thumb studs. The tape helps prevent scarring the knife blade while removing the thumb studs.
Place a 1/4-inch nut around one of each of the thumb studs on one side of the knife. Position the Kershaw knife blade between the jaws of a bench vise. Slowly close the jaws around the blade and nuts until you can release the knife blade without it falling from the bench vise.
Continue tightening the bench vise jaws until the bench vise jaw is flush on the side of the blade without the nuts. Slowly open the bench vise jaws and remove the Kershaw knife. The vise pushed the thumb studs to one side of the knife blade. The nuts allow the studs to move as the vise jaws push the studs.
Peel the nuts away from the blade if they embedded in the tape. Grasp the ends of the thumb stud with a pair of vise-grip pliers and hold the knife handle in your free hand.
Pull the stud out of the knife blade with the vise-grip pliers. Repeat for the remaining two thumb studs. Remove the tape from the knife once all thumb studs are out of the Kershaw knife blade.