Gertrude,
The transition process hasn't been published yet, so BillieBob and Robin are summarising bits of LASORS, section A10:
Note: Legislation currently under development within the European Union will require all UK national licences to be converted to the European Part FCL equivalent by a date that has yet to be decided but is likely to be within the next four years. Licences issued under JAR-FCL will be deemed to be European licences and no conversion will be necessary. However, UK national licence holders may have to meet additional requirements to convert to the European licence. It is therefore in a pilot's best interest to
consider conversion of a UK national licence which has a JAR-FCL equivalent to the JAR-FCL equivalent prior to the introduction of new requirements under EU Regulation."
As the CAA > JAR licence is an established current process, your local friendly CFI should be able to explain what is required for him to sign your logbook.
FlyingStone,
You are confusing licence with rating. I, and many others, have a licence valid for life so long as my ratings are current. I think the two year rating renewal process is a little childish, but I go along with it. There has been no measurable improvement in accident rates since it was introduced but, as you imply, it's not a bad idea to fly with an instructor every now and then.
The requirement to renew a licence every 5 years has no safety benefit whatsoever. It is purely a paperwork exercise, designed to keep paper-shufflers in employment and to keep the money rolling in to pay them. This sort of naked self aggrandisement is why people hold eurocrats and politicians in such contempt.