Pentax Zoom Wide Angle SMCP-FA 28-105mm f/4-5.6 Autofocus Lens "k100 manual" Questions

...I cannot see a way to unlock the lens on my SMCP-FA 1:4-5.6 28-105mm Power lens. I now use a Pentax K100 DSuper which cannot operate a Power Zoom, however I am happy to use the zoom manually. I was ...