Please note that for calculation purposes use 11% as the cost of capital & 30% as the company’s tax rate.
Essentially based on the facts of the case (case attached) you will need to make a determination whether to refurbish the existing finisher or purchase a new one. That will require you to identify all relevant cash flows and perform a NPV calculation. I recommend you net the cash flows so that you have only one NPV, not multiple ones.
You should submit your NPV calculations plus a one-page summary that supports your NPV calculations. This should include what other factors you took into consideration when choosing which alternative was best.