When I popped off my 1985 K30 glove box knob off, I found that all it has is a sharp inside edge on the chrome knob, which just grabs a sharp outer edge on the lock housing. The way I got it off was just to pry the outer edge on the chrome dress knob, with a large wide flat blade screw driver (use some kind of small shop towel under the blade of the driver to protect the paint on the glove box), and it popped right off. When I looked at the lock with the knob off, there was no small hole at all with a spring depress in it. It was just flat metal behind it. To install the chrome knob cover, I just pushed it back on, and the sharp inner and outer edges just locked back together.