1. FR-3 is the right tool. Don't expect it to completely bottom into the freewheel.
2. After fitting the tool into your freewheel, install the quick release just a little loosely to hold the tool in place. This is important or you'll ruin your new FR-3 tool.
3. Using a big (12" or 15") adjustible wrench, hold the wheel vertically in front of you and push downward on the wrench with your right hand. Freewheels tighten themselves every time that you pedal up a hill so it'll be on pretty tight.
4. Be sure to grease the hub threads before reinstalling your freewheel.
5. Good luck! Removing old freewheels is always an adventure.