The passage linking the two lines is at the southern end of the Line M1 platform (ie. back of northbound trains for Młociny, front of southbound trains for Kabaty). It's not particularly well signed, so if you are at the front of a northbound train or the back of a southbound train, you will pass two sets of escalators taking you up from the platform to level -1.
Below: if you get off a northbound Line M1 train, the passage to Line M2 is not immediately visible (it's behind the pillar to the right)
Below: still at Line M1 platform level - the top of the escalators leading down to Line M2. Note two 'up' escalators and one 'down' escalator.
Below: heading down the escalators. There is a lift option for wheelchair users, and raised floor markers for the visually impaired.
Below: at the bottom of this set of escalators, a short passage, then a staircase. View looking the other way towards the escalators to Line M1. Looks like the budget ran out for a second set of escalators.
Below: finally down on the platform for Line M2. The passage linking the two lines is at the western end of the platform (so back of the eastbound trains headed for Dworzec Wileński, front of the westbound trains for Rondo Daszyńskiego).
Thanks to readers An Lukasz and Marcin for pointing out my error, which prompted today's revisit and photos. Duly corrected on previous post.
Update 12 March: Take a look at this story on TVN Warszawa, pointing out just how bad signage is for the direct interchange between the two lines. [Thanks Marcin K]
This time three years ago:
Nikkor 45mm f2.8 pancake lens tested
This time four years ago:
Old Town, another prospect
This time five years ago:
W-wa Śródmieście - commuters' staging post
This time six years ago:
Filthy ul. Poloneza
[Three years on, nothing's changed...]
This time seven years ago:
A sight that heralds the coming of spring