Dennis:
I just serviced mine a couple weeks ago.
There is 1 screw on top of the shell to be removed
Remove the valve rods, note their position and keep the left and right side separated when removed
Open up the boiler front and remove the bulb from the holder
Remove the screw on right side toward front of loco. It goes all the way to other side of shell through motor
Remove the valve gear, 2 screws underside.
I also removed the pilot truck and smoke generator and cleaned that up while everything was apart.
Reassemble
If needed search for video of a 2025 disassembly, exact same as a 675
Hope this helps
JW