You need to learn to (re) write shaders. The Material GUI is just an interface for working with shader parameters.
With the shader you're already using, UV1 is used for "Base", and UV2 is used for "Lightmap". Why you'd want to switch them around, I don't know, but you can do so by switching "uv_" and "uv2_" around in its code. I assume that's what you're talking about; Unity only allows two UV sets.