Is there any easy way to mask on the bottom any vias that are not used as test points.
You can define your typical padstack via without soldermask on the bottom (Null). Then when you run TestPrep, use a via with soldermask defined on the bottom layer. Hope this helps!
How do I replace all the vias except the test point vias with this via without soldermask on the bottom?
Once you have modified your via padstack so there is no SM on the bottom, use Tools > Padstack > Replace to replace/update your standard vias (if you did not change the via padstack name, use the same name in the Old and New fields). The testpoint vias should be a different padstack name so those won't be changed.
That worked. Thanks