@atr-drivr - you'll need to a medical, the 14 exams (but not all the ground school bits, - I would recommend a refresher ground school course, one example is Bristol Ground School), then a flight test with the UK CAA observing. I'd do it in an Airbus. All of that will need to be organised by you.... So, medical at Gatwick, 14 ATPL exams (and a refresher course), some sim training to get up to speed with any EASA pecuiliarities and a check ride observed by a CAA examiner. Ta da. The check ride will be a bit like a licence skills check.