Tool - Concrete Diamond Saw Blade
DEWALT DW4712B 7-Inch High Performance Diamond Masonry Blade
http://www.amazon.com/gp/product/B00291EJ32/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1 $11.07
You can use this in a regular circular hand saw. It is best to have someone point a garden hose at the cut to keep it wet to keep it cool and avoid dust. Use a GFCI power outlet to power the saw if you are using water. Use safety glasses, ear protectors, and a dust mask.