From here it was just a matter of reassembling in the reverse order of the taking apart process. Nothing is tricky here, and the only suggestion I have is that the rear most cover, which covers the fan outlet, should be screwed in on the top with 3 screws but the bottom screw should be left loose. The side covers of the enlarger need to mate to this cover and it's a lot easier to do with a bit of play there. Also, I had to do it twice as I accidentally installed the top hinged cover of the enlarger upside down.
Here is a shot of the cover. The two screws on this surface can't be accessed with the enlarger cover on, so these should be tightened up first.
Duh.