Disconnect the battery where the negative lead connects to the body. This is under a small (about 3x5 inches) plastic cover at the base of the rear seat. Removal of the seat cushion is not required. Be sure to bend the lead so that the terminal is not touching ground.

See the owner's manual about resynchronizing the windows, sunroof, seat positions and IR locking system. It's an easy procedure for each.

Supposedly, all of these need to be synchronized after disconnecting the battery. But not on my car, for some bizarre reason. I had the battery disconnected for a full week once, and upon reconnection, everything works. The IR locking, the window auto-down, the seat memory, etc. But apparently my car is special. I have yet to figure this one out.