How do I use these workouts if I have a manual labor based job?

People with very physical jobs tend to best with a bit less volume and frequency than those with sedentary schedules, but not too much less.

While the job is demanding now, once you have forced your body to experience muscular failure or close to it with certain exercises, that labor will become less stressful and easier to perform. 

We suggest starting with the Intermediate routine and schedule and see how that goes. If you're getting stronger each and every workout on most exercises, keep it up. If not, you may want to drop an exercise or two from the workouts and add in a day or two of rest in between.