Both Allegedly_human and Isabel303668 are correct!
Allegedly_human is using the English passive voice for this sentence.
Isabel303668 is using the impersonal form of the sentence.
When a speaker or writer uses "se" with the third person singular of a verb in this manner, it can be either one of these.
Or both--sort of a verbal version of quantum duality!
No, it's also valid, but not more approriate.
They are showing you that Spanish would use the impersonal construction when most English speakers would use you, unless being formal.
EDIT: The Spanish does not sound formal, while the English How does one say...? is very formal.