this is a ship they want to board.....
If you fire your OC and blame him for the bad season.... then have the stats to show that the offense was terrible.... then show that you've fixed the problem and hired the "perfect guy" to take charge... then you have a narrative that makes sense to recruits.
But..... You need to make it public.... you need every possible recruit to see it and see it before they completely sour to the idea of coming to BYU.