like mrfixit says,
if there is no damage to the armature you can fix the brush housing parts (brushes, springs, bearing) in the frame without pulling the motor.

BUT...
if the armature is scored or damaged from brushes that were worn down too far and caused commutator burning then yes the motor will have to be removed.

You can get the motor out through the bottom with the truck off the floor on wheel block stands and get a jack with a motor cradle attachment and lower it out through the bottom after disconnecting the cables and sensor wires and park brake.

You can also get it out from the topside using a come-a-long and a strap. The manual does recommend getting the truck off the floor to gain easier access to the bottom motor mount bolts.

good luck