Write down your entire presentation with bullet points and full descriptions.
Make sure all texts (spelling and grammar) are correct. Ask for help from others if needed. Great leaders are great collaborators. Ask for input.
Read the entire presentation silently, hearing yourself in your mind.
Again, read your entire presentation silently, hearing yourself in your mind.
Walk away for a few minutes. Focus your attention on something else that is not stressful or distracting; example: the cloud, the birds, the trees, drink a glass of water, etc.
Go back and read your presentation for a 3rd time, but this time READ IT ALOUD so your ears can hear you from the outside. Read it in the same loud voice that you will be speaking in during the presentation at the DEMO DAY.
If you make mistakes when reading aloud, then start again until you can read through the whole presentation aloud without any mistakes. You need a perfect read-through, at least, once before you move on.
Walk away, again, for a few minutes. Do similar relaxing things you did in step 5.
Read the entire presentation silently, hearing yourself in your mind.
Again, read the entire presentation silently, hearing yourself in your mind.