The M475 is, as far as I can tell, a complete rear hub. If you really want to change to this, you'll need to rebuild the wheel. However, you say that the freewheel is broken, suggesting that only a part of the hub needs replacing (correctly called the freehub, not the freewheel).
To replace the freehub you need a cone spanners, chain whip, lockring tool and most likely a 10mm allen key. You need to take the wheel out, remove the axle, cassette and then the freehub. Fit the new freehub and put all the other bits back on. Make sure you don't have any left over.
See the Park Tools website for more words and pictures.
Here.