If you completed your PPL in Nov 2001 it would have had an SEP rating expiring around Nov 2003, two years later. It is now 2007 ie almost 4 years out of date. up to 5 years expired you simply need to pass a skill test with a PPL examiner who will then sign the relevant page in your licence and your SEP rating is valid for another two years from the date of test.
You will of course have to have an in date medical to use the licence and the licence itself must also be in date, check section IX on the second page of the licence for the expiry date of the actual licence; if this date has passed then, after renewing your SEP rating you must apply to the CAA to renew the actual licence for a further five years .
The training school and examiner who are going to do your renewal training will advise you - be careful about "advice" you might see on here; it's not always up to date.
Happy landings
3 Point