In all fairness, it's so simple it's a bit confusing (it was for me anyway) until you do it the first time.
All it is is a JAA examiner (not sure about a mere instructor though) writing a new date and signing your ratings page on your licence--in theory after they are satisfied you comply with the requirements (a few hours flown during the last year, a percentage of which as P1, blah, blah).
Not a big deal at all (and no cost for it unless someone decides to be a greedy bastard), but if unsure give the CAA a call, explain your situation and ask them what to do.
HTH.