I'm fairly sure if you raise the arm up, you will sees a small tab at the post that the arm goes onto. Slide the tab as far as it will go, then pull straight off of the post. No screws, bolts or nuts.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.