Yanni (Dr. Yanni Zack) has already made a good reply concentrating on the procedure of such lessons and what they should contain.

Let me add another point regarding contents of such lessons. For university students, the lesson topics should be somewhat "intellectually demanding", and one way to meet that requirement would be to base your lessons on newspaper texts as suggested by Yanni.

However, be sure to find out whether this is something that would interest your students and would meet their actual needs. If you help them prepare for an Oral English Exam at their uni (as I would conclude from your post), you may also try to find out more about this exam and what are the communicative skills in terms of language structures, vocabulary, and communicative contents required to do well in the exam and concentrate on the requirements in your lesson. I strongly suppose your students do expect "exam succes-oriented lessons" in respect of the latter; and if follow that and help them do a good job in their exam, you will do a pretty good job as well.

Best wishes of success!