When I took mine there was a practical content and can't see how you could take this as an outside candidate as to include the practical it would be something like a 6 hour exam. And there would be safety issues for a college to allow a student of whom they have no knowledge take the exam as he could kill himself.
I will assume nothing has changed so you will not be able to take as an outside candidate.
Not sure on watered down C&G 2392 though.
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