See http://www.calbar.ca.gov/Public/Pamphlets/...ingALawyer.aspx number 7. Essentially, if you go to an ABA-approved law school, and you have at least two years of undergraduate study, you can be exempt from this exam. Otherwise, you must take it. This exam is often referred to as the "Baby Bar."
Back to the OT, why go through the extra work of an exam for a warranted officer? What about the work that is currently being performed? Contracts, contract mods, PNMs, etc, so many things out there that can already be "graded."