"Sean, to permanently cure your slice you need to understand what happens through the impact area.
"Your swing path causes the clubhead to approach the ball from the outside of your intended target line, cutting across the ball with the clubface open which creates slicing side spin.
"Although you have flattened your backswing a little (which is positive) it's not productive if you then come down on a different route outside and across.
"Imagine Jim Furyk; he goes back outside then reroutes the club back inside and as we hit the ball with the downswing this is much more productive.
"Without changing your backswing, from the top I would like you to visualise your clubhead is going to approach and hit the 8'oclock portion of the ball (the inside), then feel your wrists roll more through impact thus squaring the clubface.
"It's difficult to see you grip but I suspect from your set up that your grip may be too straight (weak) and you need to turn both your hands more to your left with both Vs pointing at your left shoulder. This will also encourage the draw spin on the ball.
"From the top you should feel a little shift of the hip aiding your arms to drop inside before you turn through the ball.
"Good luck with the changes and think about seeing your local qualified PGA pro for some personal instruction to show you the correct downswing feelings and set up."