To repair the wheels on a live steam locomotive, it is about as bad.
Almost all live steam locomotives have tires just like the real ones, and they have to be replaced every 5-10 years. The process for replacing the tires is the same as on real locomotives except of course everything is 8 times smaller. Generally a 10in-18in lathe will get the job done of making new tires, or wheels. Also it is used to repair drivers.
First you have to lift the boiler off the frame.
Then take all the rods, valve gear off the frame, brake rigging, springing.
Then get the wheels out of the bearing blocks.
Heat the tires up with a torch, beat the tires off.
Make new tires on a lathe
Put tires on the wheels.
Then you got to put everything together again.

I am lucky that on my locomotive the tires on in good shape, but eventually I will have to replace them.
Have fun,
Andrew