You could tell your group that you want to present but be smart about it and choose the topic that has the least amount of words you stutter on, and ask them if you can do that part. Or, what I do when I have to present in groups is that I do the introduction and say everyone's names and the topic, and then at the very end I thank the audience and give a little memorized conclusion that I carefully wrote with words that I don't stutter on. It's all about the planning yo. If you decide not to present you could regret it for the rest of your life. Be brave and after it's over you'll be extremely happy