The steps to solve this problem are as follows.

$1.$

Calculate the change in EBITDA as a result of the replacement.

$2.$

Calculate the change in FCF$($excluding CCA tax$$ shield$)$ in years $1$ through $10$ from replacing the machine.

$3.$

Calculate the present value of the FCF$($excluding CCA tax$$ shield$)$ in years $1$ through $10$ from replacing the machine.

$4.$

Calculate the Year $0$ FCF$.$

$5.$

Calculate the present value of the incremental CCA tax shields as a result of buying the new machine and selling the old machine.

$6.$

Calculate the NPV of the FCF from replacing the machine.