You've spent the last eight weeks focusing on building strength and size; now, it's time to make all that new muscle pop by dropping your body fat. For the next four weeks, you'll improve your conditioning while continuing to gain size.
For conditioning, you need to train like a demon. You're upping the volume to five lifting days a week, plus 30 minutes of cardio daily. But how you train will also change. When you’re knee-deep in a set and hit failure, instead of dropping the weight, you'll take this as an opportunity to immediately move to another exercise and hit the wall all over again. It's an entirely different kind of challenge than the heavier training you've been doing.
Try to maintain heavier loads rather than automatically switching to a lighter one automatically. If there's an exception to this approach, it's today, since you just trained shoulders two days ago. But remember, the goal here is to ultimately be able to do more reps with a heavier load. That said, reduce the load on successive sets if you're falling short of your rep target.
Whenever you can, train to failure. Choose a load that allows you to reach muscle failure by the target rep (going just shy of muscle failure on deadlifts). The set-extending techniques work better if you go to failure. Otherwise, keep rest periods short, around 45-60 seconds whenever possible.