Tools: WD-40 and a paper clip or a push pin(ones for sticking paper/posters into the wall) - I think a paper clip would work better than a push pin.
1. Spray some WD-40 into the cap that comes with the WD-40 or some other very small container. You don't need a lot; just enough where you have a very small puddle of oil.
2. Submerge the tip of your paper clip into the puddle you've created. When I did this the amount of oil on the tip of my paper clip was barely noticeable. I would suggest you keep your amount this low as well.
3. Now patiently take the paper clip and trace the surround of the home button. Lay the paper clip horizontal to the phone to reduce the risks of scratching the phone. If you can move your button it would be good to do so in order to gain more access to the side of the button.
4. Continue with steps 2 and 3 until the button becomes smooth to pressure.
My major tip for this is to be very patient and to use as little oil as possible. Like I said the amount of oil on the tip of my paper clip was barely noticeable to the eye. It took me about 4 passes to get the button to my desired smoothness.
Hopefully this helps someone out there.
Disclaimer - This is an electrical device and following the above steps to the exact specs could still ruin your expensive electronics. Certainly not following the exact steps could be an even worse outcome. I bare no responsibility for anyone ruining their expensive piece of equipment.