As part my scraping of a worn Bridgeport milling machine back to original precision, I had to disassemble the machine components. Disassembling a Bridgeport mill is also sometimes necessary to move it into a small shop space or through a low doorway, or when using small vehicles.
Until I can get my photos and detailed descriptions posted here, let me just leave you with a list of the disassembly steps I used:
You can also slide the table onto a sturdy workbench instead of hoisting; crank the knee up or down to match the bench height.
If you have no hoist, you can improvise lifting heavy pieces by clamping on lumber or SuperStrut with C-clamps, like a medic's stretcher, and having sturdy human helpers lifting on each stretcher corner. Like a king in a sedan chair.
Don't mar any precision surfaces. On most components, almost all surfaces are precision!
The gibs and ways will be quite a mess with oil or grease. The knee will likely be filled with old chips. Kerosene, nitrile gloves, and a carton of paper towels are good for cleaning the components. The big polyethylene mortar mixing tubs sold at the building supply store are a good "wash basin".
Be prepared for surprises. I discovered the overworn saddle gib on the old machine I bought had been shimmed ... with a rough piece of metal pallet strapping.
If you want to refinish or paint an old machine, it is best done while disassembled.