I would try to gingerly pry it open. Try a thin screwdriver in the middle of the top of the cupholder. Be careful to avoid damage to the plastic dash or cupholder.

If you can get it to pivot, you are almost home. At this point, you probably need to remove the entire cupholder, reseat the spring, and then re-install it. Apply medium pressure towards one side and try to release the pivot pin on the opposite side and the cupholder should rotate completely out (free of the dash).

Follow my other procedure for re-installation.