Success! Would have helped if the dang instructions had been correct.
The instruction that come /w the Beretta sight pusher clearly state: "Push the sight out of the right side of the slide, as the muzzle is pointed away from you."
I was looking at Beretta's website and the picture showed it pushing the other direction (out the left).
I called up Beretta and they confirm to push in out the left side. I informed them the instruction that come w/ their pusher are wrong.
So I tried again, pushing the sight out the left side and whadya know, it worked!
New Trijicon night sights are now installed.