Alright, here is what I want to do.
>Destroy the fleet he has nearby to achieve orbital superiority.
>Use The Composer aboard Shi'era's Planet-Breaker flagship (Only Planet-Breakers and the Fortress Class warships have it) to digitize his ground forces and use that to create more Promeatheans.
>Destroy the device he was using to terraform the planet.
>Warp in more colonists aboard non-combat vessals.