If I had a specific answer on fixing it, I would be a hockey coach and not just a fan.
I can only see that it wasn't successful last year and isn't working even in a prospect scrimmage.
It's predictable and easily defendable. It relies overly on the LW on the wall. It highlights the Pens weakness on the left wing (the right wingers are stronger). It allows the defenders to take too much time which leads to the forwards being too far ahead of the play and bottles the puck in the defensive end. The only solution has been individual efforts to skate it out which neutralizes the passing abilities of most of the Pens skilled players.
EDIT: I think having primary outlet options that aren't the LW or up that side is important (up the middle and cross ice passes developing from that side were ineffective changes last season). Eliminating the gap that keeps developing between the defense and forwards is important (having the defense play faster, not releasing all the forwards at the same time, having the forwards cycle back).