If it's like my S70:
Remove the side pocket by pulling up on the front of it, then pulling it
forward.  This enables you to get at the seat belt bolt.

For those using these instructions on later cars with side air bags,
there is now visible a little red protector for the side bag detonator.
Put this over the detonator to protect it.  Keep in mind that the side
bags DO NOT use electrical connections, so disconnecting the battery
will NOT stop them from going off if you hit the detonator.  If these
last 2 sentences scare you, then don't proceed.

There are 4 bolts, one at each corner.  Move the seat all the way
forward, then there are plastic covers at the rear of the seat tracks
hiding the bolts.  The plastic covers just slide back.  Then move the
seat all the way back, one of the front bolts is exposed, the other has
a plastic cover.  You'll have some wires to disconnect before pulling
the seat out of the car.