Set your wet, snow-damaged leather boots on a towel, away from direct heat sources. Stuff the insides with newspaper to absorb moisture and hold the shape as the boots dry. Allow the leather to air-dry completely.
Remove and discard the newspaper.
Mix 1 cup of white distilled vinegar in a bucket with 1 cup of water. Wet a natural-bristle scrub brush with the solution, allowing the excess moisture to drip back into the bucket.
Scrub the entire leather surface to ensure even color when the boots dry. The leather should be wet but not soaking wet when you scrub it. Apply more vinegar solution as needed to clean and neutralize the snow damage on the leather.
Wipe the boots with a clean cloth to remove moisture from the surface. Crumple newspaper and fill the boots again to prepare them for drying. Allow the leather boots to air-dry.
Replenish lost moisture and counteract stiffness in the leather by rubbing leather conditioning oil into the surface. Pour a quarter-size amount of oil onto a clean cloth. Buff the leather, applying more oil as needed to moisturize the entire surface.
Allow the leather conditioning oil to soak into the leather for one hour. If the leather boots still look dry and feel stiff, repeat Steps 6 and 7 until the leather feels soft and pliable without being greasy.