Information: Ancient Model Base
This is just an informational comment. My GF has been using this grinder daily since about 1980, and it has never been maintained. I suspect that the "0602" is probably the serial number, so it would be almost the oldest that you'll find.
I saw comments saying to remove 4 screws or clips, or remove the paper label to expose the slot in the bottom of the shaft. They don't all necessarily have those.
It does have what looks like two #2 Phillips screws retaining the base. They have about 40 years of rust on them, but it looks like that's all that retains the base.
So depending on the vintage of your grinder, the parts may not be exactly the same. Luckily, these devices are simple, with little more than the motor, blade, switch, and body. You may just need to do a little more work to figure out how yours comes apart.
I only came looking to see what I'm getting myself into before I break something. I kind of assumed that the blade was pressed on, rather than screwed on. I'm glad I looked, before I broke it, trying to pull the blade. :)