How to get the battery out of a 00 Lumina?

OK, I think my husband shorted out the car for starters. There was a broken window button on the back passenger side. It had been broken for years (this was my mom's car given to us when she got a new one). He didn't know that. He took out some screw, re-aligned the button and put the screw out. Now nothing in the car works. No lights, no ding, no radio, no lights - nothing. The battery is about a year old and he wants to take it out to have it 'tested' to make sure the battery isn't dead. My thing is he screwed the car up when he "fixed" the button.

So now he's trying to get the battery out. He's got the bolt out from the wheel well, but he can't get the bolt out along side the air cleaner out. He called the local chevy dealer for any hints on what tool he needs and they said they have a special tool and he'd have to bring it in. Of course they'd say that. My mom took that batter out herself last summer, so they can take a flyer on that one. So he told me to ask out there if anyone had any info. He is thinking all he needs is a rachet on an extender. Is this so? Thanks in advance!!!