Magnolias do not much like root disturbance, so moving is always a little iffy. On the plus side, magnolias have a shallow fibrous root system so you do not have to deal with a tap root or huge root ball.

Spring is definitely the time to transplant in Z4. Prepare the new site first. Cut in a large circle around the tree with a square spade. Deepen the cut and gradually undercut as you go. Once the tree is loose, slide it onto a tarp or plastic sheet keeping as much soil as possible aroud the roots. Slide the tree to the new spot and plant it at the same depth it was growing. Mulch well and keep it watered all summer.

I assume it should now go in a sunny spot, yes? Part or full? Thanks for moving suggestions...can do!

Deborah, yes, full sun.