If you have not flown the 12 hrs since the previous relvalidation - you've got 24 months (of which 6 must be as PIC in the preceeding 12 months), then you will have to have a flight skills test with a examiner - where you must then pay his fee. You do not need to sit any ground exams. The examiner will then sign off your licence. If you have done the required hours, a CFI can sign the validation.
I think
