***MINOR SPOILERS***
Start Russell's chapter by selecting his picture from the bulletin board that serves as the DLC's menu screen.
This chapter is a fairly quick one - it's pretty much exclusively conversation, save for one moment where you'll have to move across cover. I had no issues with this part - all it took was to keep running in the direction of the cover. You'll have a choice to make at the end that can affect the overall outcome, but it's only made through dialogue choices.
Right at the beginning, you are given an option to either hide from an oncoming car, or to stand your ground. Be certain to hide, as this will grant you the "Reunited" achievement, which is otherwise missable.