Firstly it should be noted that the cutterhead comes out the motor side. and it takes the motor with it. as you can see in this picture. I believe there are only three socket head cap screws between where the motor and cutterhead which prevent this whole assmbly from being removed.
There is nothing holding the bearing assembly in place on the far side of the machine- nothing but 50 years of built-up crud...... It wsn't easy to get to this point.....
After I reached that point, the hard part was over. The next step was removing the windings from the motor- two setscrews beneath, and then slightly modifying my largest gear puller and pulling the rotor.
the last step was pulling the inside bearing. I needed another modified puller to do this- to match the extreme depth. Here is my bearing puller with extra-length studs
Seems so easy looking back, but I remeber it taking a frustrating number of hours to even get the cutterhead out. It would have helped talking to someone who had done it, as I wasn't sure when to use force. I don't rember the exact bearing sizes, but I had one in stock and I bought the other from either grainger, mcmaster-carr or MSC, They all ship overnite for standard UPS pricing and all stock a complete selection of common bearing sizes.
Pete