Well, this should be pretty easy, maybe just an npc where you enter the new name you want, and then executes something like this
Code:
public static void NewName(string _name)
{
MySqlCommand cmd = new MySqlCommand(MySqlCommandType.UPDATE);
foreach (Client.GS client in GamePool.Values)
{
cmd.Update("heroes").Set("Name", _name).Where("Name", client.Hero.Name).Execute();
}
}
Note: this is MySQL.