Replaces the user with the submitted representation. firstName, lastName, email and active keep their current value when omitted; every other field is reset to its default. Note that omitting cuid clears it, including when you addressed the user by that CUID — the identifier is then no longer available for later requests. The last administrator of an account cannot be demoted: a request that does not set admin: true for that user is rejected. To change individual fields, use the PATCH endpoint instead.