When I ask for this, I don't actually expect my students to carefully read every word of an article (and I tell them this directly). Instead, I expect them to be able to decode where the argument is being built within the article, and see where the important components are located. Much like I can take a bicycle and know where to set my eyes to see its key distinguishing features (If I'm interested in the cost of that bike, I would wonder, what kind of rear derailleur is it? you can usually price a bike by that one piece of knowledge; if I need to know if this is good for trail riding or commuting I might look at the frame geometry), I expect my students to learn to locate these key distinguishing features in a scholarly article.
Every discipline has genre conventions and there are really only two parts to article analysis: 1.) learn where the moves are being made 2.) learn how terms function in the particular discourse community that you're trying to listen in on. Like, "theory" in science is not at all what theory means colloqually. Every discipline, sub-discipline, and research speciality argues about how to define terms. So I need to see you get a pulse on that conversation. How are those particular authors defining their terms?
Don't get swamped in the details. Start looking for those two things in the paragraph prior to this one, and remember that the goals are probably the first two things I mentioned.