Lots of excellent advice in this thread so far. I'd just add that it might help to not read from a script. Just think about the message you are trying to convey, not a word for word script you've memorised. Just think about the big picture of what you are trying to say and just talk around the slides. Other tips are to try to get to the room early, spend some time in the room, get familiar with the place. Also, listen to music that pumps you up, whatever that is, music that makes you feel good about yourself. Build your self-confidence by remembering all the awesome things you've done for others in the past, how you've done well in past tasks. Have a sense of humour. As others have said, tell the audience you have a stutter and try and get the audience on your side. They are rooting for you to do well. If you stumble, smile about it, 'oh well', take a breath, and keep on going. You're gonna do great!