Substitution Options for Star Complexes?

I just started doing star complexes, but I have discovered that I cannot do either the power clean or the push press correctly. Of course I plan on working on these lifts, but in the meantime, what do you suggest as substitutions?

Also, related: The workouts are killing me. I decreased the weight from last week, but I still cannot complete even 4 sets of both complexes each workout. Today I stopped at 3 sets of the squat complex because I felt like another would make me throw-up. I’m on week 2, and this is currently what I’m doing:

Press Complex (4x)
Top Half Seated OH Press: 4x125 lbs.
Standing OH Press: 4x85 lbs.
Push Press: 3x115 lbs. (cannot execute properly)
Medicine Ball Throw: 8x20 lbs.
Plyo-Pushup: 5x

Squat Complex (3-4x)
Top Half Squat: 4x185 lbs.
Front Squat: 4x120 lbs.
Power Clean: 3x95 lbs. (cannot execute properly)
Jump Squat w/ Barbell: 8x50 lbs.
Vertical Jump: 8x

Deadlift Complex (3-4x)
Top Half Deadlift: 4x285 lbs.
Deadlift from Floor: 4x195 lbs.
Snatch Grip High Pull: 3x95 lbs.
Jump Good Morning: 8x50 lbs.
Broad Jump: 8x (skipped last week)

Bench Press Complex (4x)
Top Half Bench Press: 4x165 lbs.
Bench Press: 4x120 lbs.
Speed Bench Press: 5x85 lbs.
Medicine Ball Throw: 8x20 lbs.

I would appreciate any help you can provide.