A slow start eventually gave way to a more cohesive and organised Nigeria side, with Ahmed Musa scoring twice to put his nation back on track for the last 16.
"We changed our strategy and organisation, playing 3-5-2 with Victor Moses playing in the place where he plays at Chelsea and the captain came back to the position that he plays in China and used to play at Chelsea before," Rohr told reporters.
"I think it worked out well. They did this for the country, for the team. It was not easy to convince them but in the end they did it well. It gave us more space and the speed proved decisive for us."
"In the second half it was a different team because they realised at half-time that we had to do much more. We played against a very good team from Iceland who were better in the first half but did not score and we were better in the second half."
Nigeria's victory lifted them second in the group, behind Croatia, who have already qualified for the second round.