Jump over a piece to remove it. Keep going until there is only one left. Thats it!
Sounds simple? It is. Sounds easy? Try it and you shall see...
Tip: if (when) you get stuck, you can bring in extra pieces to help you end up with one piece on the board. And if you do so without bringing an extra one, youll earn an extra one to help you later on. (By the way, all levels can be solved without an extra piece.)
Also, you can save and share your solutions as little movies (great when your friends dont believe you or you forgot how youve done it).