Part 1: Overhead Squat
Go heavy, or just use light weight and practice mobility, with just a PVC if necessary.
15 overhead squats (95/65)
Option 2: 75/55
Option 3: 10 kb swings and 10 kb goblet squats per round instead of OHS
Modify by reducing the weight and/or the rounds.
Modify the run by rowing 450m per round.