Use one of the Low Max 45 minute premixes instead of Low Impact Step.
For the lower body cardio blast, use one of the Low Max 45 minute premixes and the part of L&G that has the ankle weights but without the weights. All of the "leg" part is just lunges, squats, and non-weighted leg lifts/glute lifts so I think that's the best comparison...or I guess you could use the floor work only from PLB. The lower body cardio blast does not use weights of any kind, just a stablity ball.