It's so easy!
Here's how: Dolphin 7.x
1. Log in as the Administrator.
2. In the bottom right is a wrench. Click it to access the Admin control panel.
3. Click: Settings -> Basic Settings.
4. You can rename your site by editing the second field, "Site Name"
Note: This does not change the URL. Only the display name in the banner across the top of the page.
(Nice feature: It also updates the name on the browser window tab! Good on you, Boonex!)