Pulling it out.

With a special "pull out gear" the rotor of the generator is being pulled out.
It's all done by hand; like turning the wheel of a barrel organ.
The mechanism squeeks a lot, it was like making music.
The men wanted to go round with a hat to collect money from the spectators.
The rotor is disengaged (uncoupled) from the turbine and slides, partly supported by the overhead crane over a special pad, covered with grease.
Here's another view.