There is no substitute for practice (as others are noting here as well). Not that it will necessarily help for this presentation, but each one does get easier. Also, one thing that helps me in work as well - is to be prepared and make sure you completely understand the material you are presenting. Feel comfortable with any props, electrical, computer equipment you are using.
Not sure if you have handouts or other visuals or are able to - but I always felt better when I had some sort of visuals for the audience to look at as well. Depending on the parameters of your assignment - getting the class involved makes a presentation more fun for all parties.
I remember doing one in my marketing class where we had the classroom participate - we broke them into groups and gave each group an assignment - everyone was much more engaged. And the fun part of it made it less stressful for us presenters.
Another thing you could do - is to mentally prepare. One thing that made me more relaxed giving a class presentation was thinking when I am the audience how do I feel about the presenter - you realize that half the time you pretend to pay attention and the other half you are not at all critical but supportive of the presenter. Realizing everyone in the audience is just like you - makes it seem less intimidating.