How do you change a nickname?

[Mark Wahle]

I have some user accounts whose nickname is their name (e.g. @Bob Smith) while I have other users whose nickname is the first part of their email address (e.g. @bsmith). There does not seem to be any pattern to which users have which setup. While I have the ability to setup the account and change their name, I cannot figure out how to change their nickname because I do not see a field for it anywhere.

This is important for me because we have a few examples where the email address reflects a maiden name while the individual now goes by their married name. Thus after a period of time no one recognizes the individual by their nickname (which has also led to the creation of duplicate accounts, but that is a different matter).

[Mark Wahle]

Forgot to mention this - when you look at the user list, some of the individuals appear as "Bob Smith (bsmith)" whereas others appear just as "Bob Smith". For those who appear as the former, when you try to search for them they will only appear if you search using "bsmith" rather than "Bob Smith". Help?