Need a Video Explaining Inferences and Contrapositive [LOGIC GAMES]

Hello friends,

The way I've decided to study for the lsat is by reading the Powerscore books then going through the online tutorial. I was wondering if someone could please link me to a lesson that explains in detail my two biggest sticking points when it comes to logic games: identifying contrapositives and making inferences.

Thanks and all the best,

M