How do I increase the total contract pay to an academic-year faculty, 9-pay-12 contract?

Just add a new row with the effective date in Job Data, and increase the contract pay amount in Pay Components on the Compensation Panel. 

Hit the "Calculate Compensation" button in yellow, then save the information. The contract will adjust for the rest of the timeframe. 

It's best to do this before the May pay cycle, so the ENP portions can adjust. 

You may also review a guide to compensation changes to contracts.