The 1228 is an idler drive TT. Most idler driven platters were held in place with a notched"C clip" at the bottom of the spindle. Typically the clip has a slot on one side which makes it possible to insert a flat blade screwdriver and pry it away from the spindle.
Be aware however that those clips were designed to be very springy and care must be taken that it doesn't go flying when you remove it. Trust me you would be astounded how difficult those little beggars can be to find after taking flight.