Please help me, I'm stuck.

To prepare for this Assignment, choose a publicly-traded company, and then estimate your company's common stock price, using one of the valuation models presented in the assigned readings or outside readings. Defend your choice of model, and explain why it is appropriate to use for your company's stock. Be sure to explain how you arrived at any assumptions regarding values used in the model. Determine whether your company appears to be correctly valued, overvalued, or undervalued based on your company's stock current price and model result. Check Yahoo Finance for current stock prices. Finally, explain why your company's stock appears to be over-, under-, or correctly valued.

Company chosen is Walmart, Inc. using the Discounted Dividend Model. Using Excel. Please explain if you can. Thanks