I’m not familiar the UA plans, but here’s the basics of Max Strength workouts.
First, you’ll need to find out how much weight to use. For each exercise, select a load that allows you do to at maximum 5 reps (you would fail to lift the 6th rep with good form).
Once you find the correct load, you’re ready for the workout. But for the workout, you’ll perform each exercise without going to failure by only performing 4 reps.
It may take several sets to figure out the correct weights, and your step-up weight may be different from your step-downs.
The general idea behind a Max Strength workout is to lift heavy to increase the pool of recruitable muscle fibers without gaining more muscle mass. Having both high strength and a large aerobic base will enable better gains in muscular endurance workouts.