If you want to remove the cages, take something like a flattened paper clip. Place the tip of the paper clip on the cage between the balls and push. If it doesn’t budge, try at another spot. The trick is to be gentle yet firm to avoid damaging the cage. In my experience, about half the cage will pop off the balls from the first push, then you use the paper clip to do the same thing to the other side of the cage to remove it entirely. To put it back it, place the bearing over the cage and use the paper clip to arrange to balls. Once the balls are in place, press down evenly over the bearing and the shield should pop back into place. Once again, gentle yet firm, try not to force anything to avoid damaging the cage. Cages and shields can be cleaned with water, soap, and a toothbrush.