If you follow the weblinks, Fozzy, I think you'll find that it's the first 100 purchasers of the deluxe Olympia (RRP £50) from each shop after 10th January who get to meet BF. That means you need to act fairly swiftly and you need to buy from the shop where you hope to meet him.
This mirrors the Selfridges process, although there the 100 winners were chosen in advance (from e-mail applications) and the purchases were completed on the night of the signing session.
On the plus side, although all the publicity says he'll only be signing the deluxe Olympia sets, he showed greater generosity at Selfridges and London's HMV store. Mind you, he might have a rethink if he knew how many "signed at HMV" items subsequently appeared on eBay... Good luck!
P.S. I'm temporarily part of BF's website; the still shot of the Youtube clip from Selfridges shows me waiting patiently in line! Not quite the 15 mins of fame promised by Warhol, but, hey, it's a start!