I don't think you actually take the exam at the FSDO. Go online to the FAA website and search for testing centres. I'll be very surprised if there isn't one near you.
I'm in YYZ and there is one in Mississauga and another at the Buttonville airport. When you call the number of the testing centre near you, they will give you an 800 number for the folks that provide the test (can't remember the name). The testing centre will receive the test and act as proctor only. When you get you result, THEN you go to the FSDO with logbooks, medical (FAA), licence verification form, Canadian licence and passport.
I'm trying to study up for any airspace type stuff, O2 regs, and looking for communication differences. Alternate requirements, departure and take off. Just don't know what to expect.
Good luck.
Kevin