Start by racing around the lake. Take off at a super-sprint and run yourself into complete oxygen debt within the first mile. Keep pushing all the way around the lake. Time your first mile and several spots along your route. Do that twice a week for 4 weeks, running each of the timed spots faster than the time before. (Alternate with easy trips around the lake on other days to recover.)
After 4 weeks of this, change this workout to a 3/4 mile sprint as hard as you can go. Start at a hard sprint and run the whole 3/4 mile as hard as your legs can go. At the end don't stop. Instead slow to a jog and return to the start to run it again and then one more time for 3 repetitions. Same as with the round-the-lake workout, twice a week for 3 weeks.
(On other days continue the round-the-lake recovery runs daily).
Now you are ready for the indoor mile, eerrrr 1500m, whatever!