Sentence:  He thinks he needs no education for that work; it is just as natural to him as it is to eat and drink; and he is ready at once to undertake the management of the largest retail house in town, only needing to be shown a day or two, "till he <WSD>learns the ropes</WSD>." 
Meaning of the word marked with <WSD> tags:  To learn the basics or master introductory knowledge.