According to Howard Epstein :
If your unit is anything like mine, there are several hex socket head bolts holding the end caps of the blade bevel axles.
In other words, when the blade is 90 degrees to the backstop (arm straight out), the saw motor will tilt on the axles on either side of the motor (one facing you, one facing the post).
Undo those and the motor will begin to fall out of its "cradle".
CAUTION: there are "slugs" embedded into the mount castings that provide positional stops and part of the clamping. Don't lose them! They may even be spring loaded, so, be careful you figure out where they came from.
You'll also need to disconnect the power wiring.
[my unit dates back to the late 60's. Massive cast iron arm.]Ask around, you may be able to get a manual online. I did.