Near the start of the chapter, you will see a red tube that runs along the side of the scaffolding. Make your way to the top and pop off your head. Drop it down the red tube to snag the collectible that is inside it.
After heading up the ramp and outside to the glass ceiling, make a left and follow the edge to the opening in the roof. Follow the beam up and it will lead to another collectible.
Beside the glass roof, there is a flag pole in the center of the roof at the front edge. Drop off the edge there and you will land on a platform behind some columns where a collectible will be spinning.
Once you drop through the glass dome and climb the stairs to the top to find the electrical box. Go through the vent to reach the far side. Once there, go through the other vent, on the left of the doorway and it will lead to a glass walled room which houses the next collectible.
Once in the main area, there will be a large battle. Once things calm down a little, go to the second floor and in the far corner, beside the door that leads to block 4, will be a standee. Shoot it to reveal the collectible behind it.
You will need to go through the doorway that leads to Block 2 to enter the next area. Through the corridor there will be some aquariums, one of which has the collectible in it. Shoot the glass and toss your head in to grab the golden cherub.
In the next room, there will be a large blue whale hanging from the ceiling along with some killer whales. Once the battle is done in the room, head to the second floor and toss your head on to the whale’s tail. Once on it, grow your body and run up to grab the collectible sitting on it.
When you enter the next main room, there will be a hanging coffin right above the entrance. Shoot it to make it fall and there will be a collectible inside that will appear when it crashes down.
This collectible is one of the trickiest in the entire game. After the battle with the large fiery puppy and the obelisk in the center is knocked over, there is a collectible high above the center area. To get it, walk up the obelisk and go to the left. There will be a table below an archway. Toss your head up to the archway and then regrow your body. Shoot the sign across from the arch to lower it and then you’re your head over to the now lowered sign. From there roll your head around the edge of the large dome to reach the collectible on the far side.
When you go through the door to reach Block 4, there will be a fire extinguisher next to a vent just inside the door. Shoot the fire extinguisher and the vent will open. Roll your head through vent and you will find the final collectible of the museum.