Depends on the rating you hold now and from where?
IE, if you have an FAA or CAA then its pretty straight forward for validation. If you have Malaysian, HKG, RPA, THAI etc... you need to write for a validation.
If you want a full licence, you have to write,,,no choice. All the exams. I think 2 for CPL/IFR and 4 for ATPL.
Cheers,
OffshorIgor