Seperating 2 small trees?

Today I was looking at an overgrown area of my yard, removing small junky trees. Strangely, I found two small trees (About 3-4 feet tall): A safras and a magnolia. They are about a centimeter apart. I would like to keep both of them, but this area is already occupied by a poplar and several holly bushes, right next to a fence. This fall when I move them, How should I seperate them safely? And also what kinds of light do they want? Where they are now is very shady.Any tips for keeping them healthy after moving?