I just finished rebuilding my third motor. Everything gets a little corroded
and sticks a bit. After you remove the motor, two bolts let you take off the
top bearing plate. then you remove the nylon housing for the brushes and the
thermal switch. Next you remove the armature by pulling it out. Corrosion in
the bottom bearing can hold the armature. I used PB blaster then gentle
persuasion  to get the armature out. On one motor, the bottom bearing pulled
out with the armature past the retaining clip that holds the bearing in the
bottom of the motor case. I had to drill through the motor case in order to
press out the clip. Let the PB blaster work long enough to avoid this.
Good Luck!

Bob Wing
88 Westy