Remove the dash bezel, the large main piece of trim that surrounds the gauge display, radio, HVAC etc.
Once that is removed there is screw that hold the ash try to the dash frame/structure. I believe there is only two, maybe 4. Should be right on the front of it, remove those, and it will pull right on out. You will have a light wire to disconnect as well, just disconnect, and hang it on up in the dash out of the way.
I don't smoke, and find the ash try useless, so I removed mine, which made the cubby hole below it much larger and more useful. Back when I did this, i also had two gauges mounted down there, which I do not anymore, but its still nice its out of the way.
Hope that helps.
~F~