The main problem with this mission is controlling Niko. I am yet agile on controlling the character and the camera at the same time, and having to stop to look around and where to run to, is quite difficult. Fortunately, in this mission Ivan almost waits for Niko on some places, so that we can have the time to point to the stairs.
Finally, I wasn’t aware that I could not kill Ivan. So, now it is too late…