Step 1 Get Prices from Yahoo Finance for four stocks - 60 observations at least

Step 2 Calculate Return = (Current Price-Previous Price)/Previous Price

Step 3 Calculate Expected return= average of all return Calculate Variance Covariance matrix - either using Matrix mult or using Excel's Data Analysis

Step 4 Assign Weights

Step 5 Calculate Portfolio Expected Return Step 6 Calculate Portfolio Standard Deviation

Step 7 Using Solver calculate Minimum Variance portfolio