EASA licences, now UK Part-FCL Licences do not expire, they are issued for the lifetime of the holder. Only the ratings contained in the licence expire. You can renew these by training as required at a DTO or ATO and passing a Prof Check. As a licence holder you can then exercise the privileges using a PMD (Pilots Medical Declaration) in accordance with Article 162 No need for a Class 2 unless you wish to fly outside the UK. If you do wish to fly outside the UK you will need a copy of CAP2086 Confirmation of Validity to go with the licence.