If you’re recording it by yourself, you can do anything. The voice recorder app on Microsoft allows to pause and the clip will pause too, so if you feel that you’re about stutter, just take that pause and breathe. I stop after every line and just breathe in. A tip that has also helped me is playing music somewhat loudly and just reading through it so my brain thinks I’m singing / humming along. Also, if you do go over the 5 minutes, who cares? You’ll feel great for getting it done and you can just let him know if it does