Attach the small brush attachment to the vacuum hose. Gently vacuum the entire surface of your leather couch to remove any dirt particles. Remove the leather cushions and vacuum beneath them. Use a soft-bristle brush to loosen dirt and caked-on stains. Vacuum the loosened dirt.
Prepare a commercial leather shampoo or cleaner according to package directions. Stir the cleaning solution to make white suds or foam. Scoop a small amount of the suds onto the stain. Use a white cloth to rub the suds into the leather in small, circular motions.
Use the brush attachment on the steam cleaner. Shampoo the stain with circular movements. Use the white cloth to blot off the excess leather cleaner suds. Repeat steam cleaning and blotting until the stain is removed.
Allow the leather couch to dry. Turn on the ceiling fan, open windows or use a blow dryer if necessary to dry the couch more quickly.
Apply commercial leather conditioner to the remaining white cloth. Rub the conditioner into the leather surface of the couch using large, circular motions.