Ali,
As you state you have a valid PPL. All you need is to renew your lapsed SEP rating. When you do that is simply down to how many hours you need to have before your course/training. Depending on how rusty you are then you may need an hour or two to just run through circuits, stalls, PFL's and then a renewal test.
I had the same situation with a lapsed SEP rating and my renewal test was basically just an hour covering the GFT part of the PPL flight test, albeit very much more relaxed.
I did steep turns, stalls (with and without flaps), recovery from a spiral dive, PFL and then into the circuit for glide, flapless and normal landings. All very pleasant and not as expensive as you would imagine. The flight test standards are on the CAA web site, if you do a search for "flight test standards", although I can't recall which standards document number it is. I believe the actual content of the flight test is down to the discretion of the examiner, but the standards for the evolutions are the same as those for intial issue of the PPL. Although not always included, I believe the examiner can also ask you to complete a Nav route, if they so desire.
Regards,
Obs cop
Last edited by Obs cop; 5th May 2008 at 15:01.
Reason: To add the nav bit