i worked it out, if anybody is interested:
remove blade, remove brushes, disconnect laser, remove 4 screws mounting the motor onto the chassis, remove motor housing, remove 2 screws which hold the armature in place, remove armature, remove arbor assembly from the blade side, remove small bearing from the back of the arbor assembly (puller required), remove cir-clip, remove bevel gear, woodruff key, seal and washer, remove arbor and bearing from casing, separate bearing from arbor shaft, re-assemble in reverse order, fitting new bearings, bevel gear assembly requires compression to re-fit the cir-clip. good luck