If you have a Propeller Suit and are super quick you can grab this one right off the start by jumping up and left. Otherwise pick the middle path to get to the this coin. Then pick the top section to move on.

You need to be big to bust out the bricks. Then wall jump to the Star Coin. If you miss it pick the top of middle section to loop back. Pick the bottom section when you are ready to move on.

Hit the P-switch to activate the bricks so you can get the final Star Coin at the bottom of the map. The hurry to the right to go through the coins in the middle before they turn back into bricks.

There is a powerup in the right brick before entering the final battle. Roy now hides in the pipes from the ceiling and drops down to ground pound. Jump as he drops and land on his head, You guessed it, 3 times.