yes, you need to do all the 14 exams. To do the skill test (check ride) depends on level of your experience. Have you flewn aircraft that is required to have a type rating, certified for 2 crew, and you have 500 hours in it. If yes, you can simply take a skill test on that type of aircraft once done with 14 exams. If most of your time is in Piston aircraft or instructional, then you need 2 skill test. One for CPL and one for IR.
Expect hard core studing,, this is not FAA,, FAA is a joke compared to JAA (theoretical part).
If you don't have the right to work in Europe, don't even waste your time converting.
Ground school for JAR,, I highly recomend Bristol Groundschool
good luck