I've always used my band-saw but a coping saw, although slower, would work and is cheap. Final shaping done with a dremel sanding drum followed by hand polishing of the edge.
As you can see from the above responses, there are many methods that work it's just a matter of the tools at hand and/or how much you want to spend to accomplish the task but fortunately Lexan/ Acrylic is pretty easy to work with.