There isn't much to do the week before the race other than to be simple and smart.  Don't try anything new - not a new activity, not a new food.  It's very easy to not try a new workout and avoid excessive weigh lifting but beware of activities that could blindside you and impact your performance.   For example, raking leaves is a common practice in September. Don’t do it the day before the race. Take it easy and just store up all that energy for Sunday morning.  

Be sure to eat well, stay hydrated and do your best to get several solid nights of sleep.  Anticipate a restless sleep the night before the race but don’t worry about it.   It's very normal and will not impact your performance as long as you rested during the week.  

Review your training log if you’ve kept one. Don't fret over missed workouts and count on some serious adrenaline to carry you through the course on Sunday.