It's been about two months since I extended the hood on mine, but I believe it unscrews in the "normal" counterclockwise direction (when viewed from the front). It shouldn't be tight at all when unscrewing it or extending it.
I'll double check when I get home later today.
UPDATE: yep, counterclockwise to loosen, then pull to extend hood, continue turning counterclockwise to lock the hood.
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