Using the footnotes to the financial statements and other information available elsewhere, try to identify and estimate specific cost items that are included in the expenses such as advertising, rent, etc. Some of the specific costs are listed in the 10-K report, while many others need to be estimated based on available reported facts on the firm. As getting exact numbers is rarely feasible, what matters is the big picture understanding of the firm's internal structure and external environment. When estimating a cost item, set up a set of reasonable assumptions based on relevant facts and make the assumptions explicit. Explain what strategic insights you could get from analyzing operating expenses more specifically.