Hi!
Yes, as the lengths of the shafts are not something standard, you are supposed to but a larger shaft and cut it in pieces (or find someone that can cut it for you).
You can use several tools: A simple and cheap metal saw, A dremel or similar tool with an abrasive cutting disk, a grinder machine…
I guess that there are many tutorials on youtube, but here you have one explaining how to cut metal with a saw.
About safety, I would recommend you to use globes and safety glasses 😉