Hey! So I think that the fact you need to put a little something about stuttering in your report is a blessing in disguise. You could try make the report humorous and tie in that you have a stutter at the start of it? Humour can make it a bit less serious (on your behalf) and chilled-out. You said that your group mates know you've got a stutter so that should also help you a bit. I'd personally go along the lines of "Hi everyone! First of all, ive got a stutter and todays report is on... stuttering and conversations with others with stutters. So please bare with me!" Its impossible to write down how im actually saying that but try be comical about it. intentional long pauses, smiles, laughs etc. Overall, no matter what you do, no one cares about your stutter apart from you. The report will last 10/20 mins? its such a minority of your day! youve got this Id also be up for a conversation :)