We just finished replacing the old comms-style 650mm deep rack up in the Sky Tower with a 1000mm deep rack, so that we can actually install full depth equipment (like most modern UPS systems, Juniper routers, etc).
This involvled unloading all the equipment from the rack, piling it up in a pile next to the rack, uncabling the rack of years worth of optical and copper network cable installs, unwiring the 240V system, lighting up the network kit while it was in a pile on the floor, to restore domestic connectivity to customers, then physically unmounting the old rack, bolting in the new one (and sinking bolts into the concrete to anchor it), RE-WIRING all that other crap previously mentioned, in reverse, then re-patching everything and doing systems checks on it all.
Started at 0100, finished at around 0545 or so, though I then had to go back and do some other stuff that I’d missed in the first round of checks, so finished at around 0700 for me.
Fucking. Mission. Like. Woah.
The new rack, however, does look very pretty, fits anything we care to put in it, and has proper ventilation unlike the old one.