Stand in front of the bar with your feet at shoulder-width apart and far enough in front so that you are leaning (backwards) into the bar. This means your body will not be perfectly vertical as in the standard Smith Machine Squat. Get ready to unlock the safety hooks to begin your initial squat. This is your starting position.
Unlock the safety hooks and squat down all the way until your legs are bent more than 90-degrees. Once at the bottom, push up hard with your legs and get back into the starting position but remember not to lock-out your legs. You should always keep tension in your legs for maximum results and movement efficiency.
Finally, repeat the entire movement for the desired or prescribed number of repetitions.
Perform this exercise in a smooth and fluid motion
Keep your back straight; don't be hunched over
Don't extended your legs to the point where you lock-out your knees at the top portion of the movement
SPECIAL NOTES & LEVEL of DIFFICULTY VARIATIONS
To increase the level of difficulty, slow down the movement or increase the weight.
The lean back makes a world of difference when it comes to executing this exercise because it shifts the weight to your hamstrings more (compared to the standard type of smith squat). This is an excellent exercise if you want to put more muscle onto your hamstrings, and at the same time, it will give you plenty of muscle-separation that results in enhanced definition.
The key to this movement is not to rush it. Proper pace is equally important as proper form.