GC-Prevue - Align Layers

GC-Prevue is my favorite Gerber Viewer.

To align layers select a pad or feature that exists on both layers.  Select all objects on the layer that is to be moved.  Place the cursor near a pad, press S (select) key to center on the pad then press the Z (zero) key.  Press space bar to move (unlock) crosshair.  On the other layer place the cursor near the same pad, select S key, then O (offset) key, then OK to align the layers.   

select edit mode (press e key) for the layer the is to be move


Thats it !