Excess Market Return and Equally weighted industry portfolio

Hi Guys.

I need some assistance about Excess Market Return (EMR) and Equally Weighted Industry Portfolio (EWIP) calculation. Suppose I want to calculate EMR and EWIP for a given industry ''J". Whereas, industry “J” consisting of A, B,C firms. what is the step by step procedure for EMR and EWIP calculation?. Your cooperation will be highly appreciated.