Hi Doug,
There are some old Eat3D videos that cover Xnormal basics not sure if this is of help.
Basically what Xnormal does is transfer the highpoly mesh details to the low poly mesh. Both the high and low poly models have to be at the same scale and position in order for this to work.
https://www.youtube.com/watch?v=5n8XsbrUxNI
https://www.youtube.com/watch?v=e8M4wrCBcDE