Complex sentence: The trains first stopped in Nikolayevsky Railway Station, got to the ring at the Presnya Station, and then separated into two, one train running clockwise, and the other one running counterclockwise.
Split into simpler sentences: The trains first stopped in Nikolayevsky Railway Station before joining the ring at the Presnya Station. Here trains were divided into two, with one train running clockwise, and the other one running counterclockwise.