Hey peeps.
I'm on the roof, uploading the important radio message. I get the bla-bla-bla, but after that I have nowhere else to go.
The map just makes me walk in circles. Anyone got any tips?
 
EDIT: It tells me to go to "Station Black, to find Ulman".
This doesn't help me find my way, but I guess it's something.

I've figured it out. When you are on top of the building, go back down to the broken stairs. There should be a small opening at the very bottom. 
 Hope this helps anyone that runs into the same problem as me.

Yup, there are a few points in the game like that, where the way to go isn't well marked. A bit annoying, but the game is excellent nonetheless.