Haven't had mine out yet so I don't know what the tumbler looks like underneath. Is it drilled and threaded? If so there should be a screw and washer holding it in which apparently has fallen off. Otherwise I have seen others with a washer with a rectangular or square hole that is swaged onto the end of the tumbler.
Hey tommy - did you ever figure this out? I'm having the exact same problem with my '99 Boxster. The console is locked, and because the cylinder keeps coming out every time I try to unlock it, I can't open the console at all.
Push down on the armrest as you try to open it.....might work. Or you could do what I did and have a thief just break it open for you.....then you have to fix it.