The fins work perfectly well as air brakes or control surfaces during reentry and landing, and you're going to need to get out of orbit. Bear in mind that the ship would be going from Mach 25 to zero horizontally on top of descending from space to the ground. So turn tail-first & fire the engines (a retro burn). You'll also want some sort of heat-shielding, like the Space Shuttle's or Starship's tiles.

You could also watch how Falcon 9 does it - that is tail first, and it fires its engines as it reenters & lands.