I don't know anything about this specific product, but wouldn't the procedure consist of: 1: remove original subplatter, and 2: put new one in? Of course, if the spindle is trapped in the bearing, than you'd need instructions for that, and perhaps they have a specific new mystery oil they want you to use. Though you think they'd include it.
Be that as it may, I'm glad you put it all together. Does it sound better?