Summarize the following:
Before you darken the leather, you need to remove dust and dirt or it will get trapped in the leather during the darkening process. Use a vacuum attachment or a brush to remove any excess dust on the leather. Put the dish soap into the rag and run it under the faucet. Agitate the rag so that suds start to form, then wring the rag out. You want the rag to be damp, not wet. Wipe over the leather in small, circular motions. Continue working over the leather until you've wiped down the entire thing.This should remove any dirt buildup. Wipe away any traces of the dish soap from the leather with a damp cloth or rag. Let the leather air dry before applying any oils, polishes, or dyes. To prevent cracking, dry the leather out of direct sunlight. When your leather dries, it’s ready to be darkened.

Summary:
Vacuum or dust the leather. Put a drop of mild dish soap into a damp rag. Wipe the leather down with a mild dish soap and water. Wipe the leather down with a damp rag. Let the leather air dry.