Finding a test site to take FCC Commercial License exams would require traveling long distances and being there on specific dates. We all owe a lot to the CAs. Understand that some CAs are electronics instructors in schools who cannot just drop what they are doing and administer an examination for you. Be sure the CA knows which exams you want to take. Bear in mind that military education offices are usually less aware of the details of the CET and FCC programs than civilian electronics technical schools, thus you should be aware of the rules and options of the program and help to make sure you are taking the correct exam and abiding by the other criteria of the FCC and CET programs.
Many public libraries offer to administer exams.
You do not have to register in advance for ETA exams and you pay the exam fee at the time of the sitting for that exam. A money order, or your charge card numbers are the preferred method of exam payment. You can help your CA and the ETA Testing Staff by making sure you include the examination number on your information sheet as well as on each answer sheet. Be sure every word you write on the information form is legible.