To access the guild administration page, go to "Guild" (click on the expand button on the bottom right of your screen then you'll see it.) The click on the menu button on the upper-left on the window. You can send invites, change your guild description, and change your guild flag there. To boot members or change their rights, go back to the guild page, then click on the member you want to edit and go to "Member Settings". You can give them a title, change their rights, or boot them by clicking on the red X button next to their title.
