You'll need to use suspension training straps or ropes with handles for this variation.
If you're moving to your left, the sled will be on your right side. You'll pull the sled towards your left by continuing to cross your right leg over your left leg. Then, go the other direction by positioning the sled on your left side and dragging it towards your right side by continuing to step your left leg in front of your right.
You'll want to use a weight that's heavy enough to force you to lean away from the sled, which also forces you to drive with both legs.
Gary Homann isn't your garden variety weightlifter. Sure, he's 180 pounds at 6% body fat. Sure, he had the best 500 meter indoor rowing time in the world last year in his class and he's been an ACSM certified health and fitness instructor for the past nine years. But Gary's also got a Master's degree in applied health psychology and is currently working on finishing his Ph.D. in psychology.