I would just very carefully cut them out and stick them with some glue. As long as they are stuck down nice and firm you could try drawing round them with a permanent marker, something like you'd write on CD's with then peeling off the template. Grinding round the paper template would be difficult but not impossible, it will probably scorch and dissolve with the dunking though.
Else, look at the template, and go by eye. Making picks by measuring the keys to locks or just by examining professional lock picks can be done and in fact after you've made a few you'll probably want to tweak the designs to suit your style or target lock at some point anyway.
Good luck
