How do I approach and ask out women in a limited time frame, especially during the last day of class lectures?

There are some girls in class that I like. I haven't seen them that much quarter long since they only came for tests and quizzes.

My last class lectures are on Monday and Wednesday, and my final will be on Wednesday. How should I proceed? I don't want to come on TOO strong, but I don't want to miss my chances.