IPD may have instructions on their site for putting the bearing back in place. Those hub and bearing assemblies have been known to come apart in shipment.

The balls must be pushed a short distance outward from the center of hub. The race that fell out controls the balls with the ridge you will see on it. When you insert race the balls go into the inner race and the ridge on outer race stops you from inserting it. Push the balls outward and insert the ...