Undo stable upgrade?

[B__B__]

As the title says, is there a way to undo the stable upgrade that increases the size from three to six mounts and go back to the basic version? I upgraded the stable without really knowing what the upgrade would do, but have no plans to have six mounts, so all the upgraded stable does is take up space.

[Lightingale]

You might need to demolish it and build a new one. It's not too expensive for mats

[Sketch Elder]

Load the last save before the upgrade is the easiest method.