mad-jock, no it isn't the 'same as a ppl test but they miss out the nav bit', what carbonfibre has to do is to fly a SEP Renewal LST with an Examiner. No IF, slightly fewer stalls, slightly fewer circuits and some items are 'optional' rather than 'mandatory'.
This can be completed in around 45 minutes if it goes well; the Examiner can sign your Certificate of Revalidation/Renewal immediately afterwards and the CAA fee is...........nothing! (Unless you've let it lapse by more than 5 years, that is).