In this video tutorial : Best 3 Pipeline Glitch Tutorials
On the middle building
1) go into the middle building and go up the stairs
2) walk until you can’t go further and jump on the metal railing
3) let a friend crouch on the metal railing right before the first room in the building
4) jump on him so you can get on top of the first room
5) now take your rocket and rocket jump on the metal bars
6) you can now walk around on the middle building
In the pipes
1) go in the cellar of the middle building
2) now find a room with some pies and a fence before it
3) jump crouch on the fence and you will sit on a very small ledge
4) lie down and look forward
5) you are now in the pipes
In the towers
1) go west of the map where you see 3 containers
2) get a friend crouching in front of the first container
3) jump on his head so you can get on the container
4) get another friend friend crouching in front of the second container
5) jump on his head so you can get on top of the container
6) you can now jump over to the towers