This was extracted from the Printrbot Simple Metal Fusion 360 Diagram. Would be ideal for a replacement make or testing before you attempt to press out or in bearings. The original part is discontinued.
Technical
No recomendation from my end, this is for you to experiment with, however I would strongly suggest printing it 100% solid and using the strongest material available to you, since the original part was made from metal. Please tell in the comments, what you used, because it may help someone else along the way.