From this post, I got the idea to remove and replace the wheels altogether using a hacksaw.
Here’s what it looks like right now. My problem now is that I can’t remove the leftover metal shaft from the caster wheel.
I’ve tried using some lubricant and hammering it with a screwdriver but it didn’t budge.
Yes. Replace the whole caster. Whats not standard is the diameter of the wheels, which for luggage, i would keep them the same size or a similar small size. To keep it from being too top heavy and to make sure it fits in the overhead compartments of a plane. Double check your casters to make sure they have standard stems/the same ones as the ones you want to purchase.