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.
Are the stems on the caster wheels standard in length?
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.