[Outbackmark]

Open the DB, click on the table in which you wish to change the value (usergroup), click structure, then click the little pen(change) to edit the field you wish to change (title). Change the field lenth/value and save.
This is fine if you are not entering huge amounts of code, but as vbenhancer says, and particularly if you are doing something large or something you want to use in multiple groups etc a CSS class would be the way to do it.