Complex sentence: On the loop, at Ullevål stadion, the line number changes to 6 and the train continues around the loop, through the downtown section a second time, before leaving downtown on the Kolsås Line in the west.
Split into simpler sentences: On the loop, at Ullevål stadion the line number changes to 6. The train continues around the loop, through downtown again, leaving on the Kolsås Line in the west.