I believe this is the tool you need (since it would appear that there are only two notches in that freewheel):

http://www.ride-this.com/index.php/p...tool-fr2c.html

I've you've never done this before: removing a freewheel can require *QUITE* a bit of power. Forget about just putting the tool on there and using a crescent wrench to turn the wheel off. You are going to need a heavy vise that is mounted very firmly on a table to put the freewheel tool in. Mate the freewheel with the tool and turn the wheel to release the freewheel. I've also had luck using an old steam radiator but that was with the white industries freewheel removal tool (which unfortunately will not work with the freewheel you linked to).