Section 13 (Starting/Charging Systems (H4SO)): Battery: Removal
WARNING: This page is about a different car, the 2005 Subaru Outback and 2005 Subaru Legacy. However, it is still accessible from the selected car via links, so may be relevant.
Disconnect the positive (+) terminal after disconnecting the negative (-) terminal of battery.
Remove the flange nuts from battery rods and take off battery holder.
Fig 1: Removing Flange Nuts From Battery Rods And Take Off Battery Holder