I can also confirm the monitor itself is a giant pain in the ass to get out. However, the chassis is quite easy.

I have done a tube swap on mine and it sucked. Good to a have some help if available.
Once it's discharged properly, there are two screws that hold the chassis to the cab, next disconnect power, anode cap, sync and color cables from the main board, yoke, and degauss wire (you may need to cut or desolder it from the neckboard. Cutting it will be easier). I think that's it.