What you will do, is to dig out the inner black cover with a small sharp screwdriver. Next, you will see the locknut surrounded by a metal sleeve. Chop up the metal sleeve with some cutters. Mangle it until you have full access to the locknut. Now, remove the locknut completely, and pull the metal sleeve (which you just destroyed) off. Adjust your ALDA if necessary, and put the locknut back. Also, you might find it useful to use a colored permanent marker to shade part of the adjusting screw, as a way or marking the original position of the ALDA.