Have everything the same right up to MitB because that part was actually executed well and generated a huge buzz. I'm pretty sure a fair amount of old fans came back to watch The Rock and stayed because of the Punk storyline, viewership plateaued somewhat around that time, it were still declining but not as steeply as the overall trend of the previous decade.
After MitB Punk should have stayed away for longer than 2 fuckin weeks. They could have kept him off TV and promoted him in other ways.
>Have him do talk shows where he's introduced as "former WWE superstar CM Punk"
>have him wrestle or at least appear at a few high profile indie shows
>maybe even run ads during Raw's commercial breaks as if Punk bough himself ad space. Doesn't hurt to think outside the box.
Remove Kevin Nash from the storyline. He added absolutely nothing and it went down like a wet fart. Same with Triple H.
Have Punk return at the Raw after the Royal Rumble to confront Cena, who won the Rumble, at the end of the show. Both are holding their belts. No words spoken.
Lastly, have Punk cut his return promo the following week on Raw, insulting Cena by calling him an interim champ and a seat warmer. Triple H comes out to accost and confront Punk regarding his absence and his attitude. Triple H has the opposite view to Punk to where he thinks Cena has the legitimate claim and Punk has nothing. But he agrees to insert Punk into Cena vs Rock at WM but only if he can beat Hunter at the PPV between the Rumble and Mania (I forget which it is). Punk obviously wins this, Wrestlemania is a triple threat, Cena goes over.