[sdiy] Swapping copper layers in Eagle

[Aaron Lanterman]

In Eagle, Blue is the bottom copper layer, and Red is the top copper  
layer.

Looking at one of my boards, I'd like to swap the top and bottom  
layers, i.e. make all the Red into Blue and all the Blue into Red.

Is there an easy way to do this? Searching through the Eagle  
documentation and various Eagle related websites is yielding no fruit.

- Aaron