I wanted to change it to something... more universal and I don't want to start from scratch since I've had it for so long. I've looked up if it were possible and read that it could be done by support ticket. But I wasn't sure if that was true or at least still true.
Support can change your guild's name for you. When you submit a ticket requesting the change, you should include at least 3 options in order of preference, in case your first choice is already in use.