How to understand what to do if an Incorrect 'Login Name' has been created in Confirm

Product Feature: User Account
A Confirm OnDemand user spotted a typo in the ‘Login Name’ (not 'User Name') of their User Security page and raised a Technical Support Case for this to be corrected.

There isn't much that can be done about this. This is because the user was created incorrectly in the first place but it is fixed, effectively underpinning the account.

Removing the record and recreating is strongly not advised.
UPDATED:  September 28, 2017