To stay in slow motion, all you have to do is, at the begining of a mission throw your light saber using force and while the light saber is still out ofr your hands go into slow motion. Once it starts to speed up again keep hold of force and keep pressing the slow motion button. If you have done this correctly you should stay in slow motion for the rest of that level. You will have to re-do it for each level. This is more a glitch than a cheat.