Before the floodlights are removed temporary cables are placed across the stadium to keep the towers stable. The lights are then taken down in pairs. Each pair of lighting towers is lifted and lowered to the ground using cranes with a 600 tonne lifting capacity.
Work to construct the new 45,000sq metres roof begins in the spring. It will be completed by spring 2015 when final preparations for the Rugby World Cup will take place including installing concessions, toilets, turnstiles and hospitality areas.
More top news
A police officer who spent six days crawling the London Marathon in a gorilla costume has finally completed the 26-mile route.
The victim of a "violent and sustained attack" on the top deck of a London bus has been named as Archie Sheppard.
Transport for London has made the badges and accompanying cards permanently available after a successful trial in autumn last year.