Last month, London's BFI movie theatre on the Southbank had to have its 26m IMAX screen replaced after 13 years of loyal service. A team of 10 riggers tore down the old screen before hoisting the new 800kg screen into place. Thankfully, BFI uploaded all the photos from the replacement.
Sydney's IMAX theatre (the world's largest IMAX screen) underwent the same treatment not too long ago. In another life, I went and saw that first-hand and it's an awesome process. My video report from ZDNet below.