First of all, you need Java in order to run Sudokuki.
If you don't already have Java on your machine, you can find it here:
http://www.java.com/
http://openjdk.java.net/ Download a Sudokuki binary... インストール方法を見る
使い方
Sudokuki is easy to use. Just try it out and have fun! 使い方を見る