It depends how bad the lean is Josh, and also how you're built. Heavy (subjective) forward lean isn't necessary indicative of bad form, not everyone will squat pretty. I certainly don't. At various points I've tried to 'fix' my forward lean, there was nothing to fix though. That's just the way I squat.
Having said that the biggest contributors to good form for me are:
1) Toes out, knees out so I can drop between my thighs rather than on top of them.
2) Slightly higher bar position. On top of your rear delts is fine, I've seen some guys take low bar too far.
3) Drop faster.
4) Stretch prior.
The best thing would be to see a video of a max set. We can go from there.