So to be upfront, I very new to SW CAM and cnc machining in general. I've been working with SW for a decade or so but only recently decided to give machining a go so please bear with me if this is a dumb question. I have a relatively simple part that I need to machine from two sides (top and bottom) on a 3 axis machine. Though I haven't actually made chips yet, the top side program appears to be set up appropriately. Due to stock size and part geometry I have about .25" to face off the bottom to be followed by some surfacing cuts to finish it off. Currently the 1st setup does all the topside work as well as the part perimeter down to the full depth of the part. The part is flat on top and has parallel sides only on the top edge so the finished surfaces provide both Z location and good gripping areas to do the bottom whereas the bottom does not give me a lot of fixturing options to do the top which is why I chose to do it this way. The leaves me with the possibility of the machine spending a lot of time cutting air in the second operation before it gets to the actual surfacing of the bottom half. Alternatively, I could run the top half and only remove as much of the perimeter in Z as necessary to grab the part for the second step but my current approach allows me to test the part without going through the second operation if I choose/need to do so as the bottom detailing is strictly cosmetic. Given that this is a one off part, neither of these issues are hugely problematic but it's a good learning opportunity for me.

So after all that explanation, my question is, how do I flip the part in SW to machine the other side of it while taking into account the material that has already been removed?