To open the slice box go to SURFACE>SLICE
When the box opens everything is greyed out and the menu instructs you to select the relief you wish to slice.
On selecting the relief it will tell you how thick your relief is - in this case 9.915" tall.
On separating them it looks like this...
When I look in the end view I see they are all on different levels. I selected them all and them dropped the reliefs to the bottom of my plate.
At this point they can be tool pathed and cut from 2" material.