Don't know what to tell you then except buy a windows PC (that was meant as a joke).
Seriously, though it's not a "home" key as such. I believe you have to press function+left or some goofy ass stupid MAC mystical key combination, because we all know less is better! LOL. If Jobs has his way the MAC keyboard would have ONE button on it!
You could send your model to a friend with a real keyboard have 'em change the pivot and send the model back to you! (sorry but I personally hate MAC's so I cannot resist any opportunity to poke fun at them).
Go here and watch it might answer your question and if it does not then not joking - get a windows PC
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675