You combine the Income Statements like you normally would (see the previous question on this), and then you do the following:
1. Combine the buyer’s and seller’s balance sheets (except for the seller’s Shareholders’ Equity number).
2. Make the necessary Pro-Forma Adjustments (cash, debt, goodwill/intangibles, etc.).
3. Project the combined Balance Sheet using standard assumptions for each item (see the Accounting section).
4. Then project the Cash Flow Statement and link everything together as you normally would with any other 3-statement model.