I don’t know that anyone has ever asked this question, let alone answered it:
How does Superman get a haircut?
I mean, he’s invulnerable, right? Indestructible. Bullets bounce off him like spitballs. So isn’t his hair like the rest of him? If you could cut his hair, wouldn’t you be able to cut him?
By now he ought to look like Cousin Itt from The Addams Family.
And how would he cut his toenails and fingernails? The scissors or nail clippers would just break–right?
Someone ought to have thought these things through.