Go to the south until you reach a 4 storey factory.

Go in the building and go to the 3rd floor. When you are there, go to the wall that's farthest to the south and go to the window closest to the stairs (it's an open window).

Jump on the window ledge and try to prone. If you are not able to go prone get off the window ledge and sprint towards the window. Jump on the ledge, but whilst in the air press B twice to prone.

When you are able to get prone, crawl out the window until you are on the edge of the ledge and jump onto the pipe.