In those grade levels, I believe a teacher should use a lot of visuals and kinsthetic activities in their lessons. A teacher could possibly show students images of different authors and illustrator, along with the books they have created. While reading the books, the teacher will reference who did what in the book. Basically explaining that the author wrote those words to match this illustration drawn by the illustrator.

Since this is a skill that the students must master by the end of the year, I think using all sorts of activities would be beneficial. I would start out by introducing what an author and illustrator all. Do several activities that involve this language including allowing them to act as an author or an illustrator. Then, I would model and explain every time I completed a read aloud or talked about a book who the author and illustrator are. I think modeling is such an important strategy at this young age, and I would make sure to have modeled it so much for the students, they can mimic what I have done by the end of the year.

As far as knowing what the author and illustrator do, I would have them complete a sorting activity as a whole group activity. Using a smart board or colored strips, write the different jobs of each and have students come to the board and sort them. I hope this helps!