Jinkster,
What FFF is absolutely correct, however in my experience a frighteningly large number of people have missed one vital step in the process. Whether you choose the "by experience" or "LPC" route to keeping your SEP rating valid, you MUST get the EXAMINER (not the instructor) to sign your LICENSE (not your log-book) BEFORE the rating expires (it cannot be backdated). It's amazing how many people have managed to miss this step, and if you do, the only option is an LPC with an examiner.
Happy landings,
MD.