You use a tool called a "froe" to split shingles. You can find one rather easy from someone that has antique tools or even lehman's hardware. The "froe" is basically a short handled tool that is in the shape of a "L" the handle being upright an the steel part being perpendicular.Take a 2' block of dry cedar and pound the froe into the block - then just give it a snap and you have nice single. It will not be as perfect as resawn singles but people used these singles for a long time!!! Good luck!