XF 1.5 How to Change Username in Quoted Text to reflect New Username?

Hello,

How can you change the username that appears in the old quoted texts of a user in order to reflect their new username and avoid confusion?

Thank you.

 

Thank you for the quick and thorough reply. How come this isn't done automatically when changing a Username via the Admin panel? Is there a downside to doing this?

 

Out of curiosity, why isn't the quoted text dynamically linked to the user, and being that the case, why isn't that query above run automatically when changing a username if there are no downsides? Thanks.