Savage,
No requirement to sit all the exams, just air law and instrument rating. You will need to complete a instrument rating flight test.
Next year with Part 61 introduced, you will also need to do an ATPL flight test.
If you do the conversion now, it will be easier. The requirements for testing officers for the ATPL flight test will be hard to achieve for many people, so I dont think there will be many about.
