biggles152. As a PPL holder you will be exempt from the written
examination in Navigation and Meteorology.
You will still need to take and pass the Law and Procedures written exam and pass the passed the examination for the grant of an aeronautical radio station operator Certificate of Competence, as well as being able to speak English fluently.
Following the succesful completion of these exams you would then be issued with a FISO licence. Before that licence can be validated you would then have to undertake a minimum of 40 hours of service provision under supervision at the aerodrome that you are to work at. A maximum of four hours training per day can be counted towards this total. You would then undertake a Validation Exam, conisting of a practical and oral test - this is geared up to local aerodrome procedures, local airspace knowledge, ATS facilities etc.
Once this validation is succdesfully completed you can then work unsupervised.
After this you must provide the at least once every 90 days or perform a revalidation.
As a minimum, every two years you will have a further Validation Exam.
You'll see that in practical terms therefore you really need to have a job lined up at your local FISO unit before beginning training.
CAP427 covers all this in detail, but hope that helps. I will see if I can find some practice exams questions for you over the weekend,