This is the method I used when I had carpeting. I now have hardwood floors and no need to worry about carpets anymore. It worked for me.
1. Scrape off as much of the candle as you can.
2. Get your iron and plug it in near the melted wax.
3. Get a paper bag, cut it larger than the wax spot, and lay it on top of the wax.
4. Iron on top of the paper bag, applying heat to the wax spots. Keep checking to see if the wax has lifted on to the paper bag. Once it has all been lifted, remove the paper bag. If there is still a little wax left on the spot, do it again. Once all of it has been removed, fluff up the carpet or vacuumn. You should not see a spot.
Freezing it with ice cubes is also a method.