Joey,
Make sure you have the right type knob first, should be a type B if you're replacing one on an 08 or 13 Stella.
The old knob has 2 bearings, one at the top of the shaft and one at the bottom. You'll need to note where these are when you take the old knob off and reuse them when you put the new knob on. The new knob does not come with any bearings. When you put the new knob on make sure the bearing at the bottom of the shaft is seated properly in its housing and make sure you put a good amount of grease around both when you put them back.
Regards,
Trev