So I'm due to bamboo slicer and I couldn't find how to do this. I wanted to put the little logo on top of the other piece. No matter what you do you cannot move the z-axis unless you do the following. Now what you want to do is press the shift button then use your mouse to drag over the entire area and select both models.
You then want to right click go to assemble. Now you'll go across to the global on the other side and click objects which is the right hand side. once you've done this you can actually highlight the piece you want to do in this case the logo as you can see now we can actually move the zed as we want to so we can move it up down and around so just work out where you want to do it turn it rotate it scale it as you want and then you can go ahead and just slice and print i hope this helps thank you