You just have to conserve your angular momentum, and that's why the name of the game is Conservation of Angular Momentum.
First, you sit on the chair, get big initial I, a big spin, (then get a smaller I).
And thats how the game is played.
I made it with Lego, but the software isn't from or using the Lego package. I wrote my own operating system with a M68K that supported threading to do this.