Change labor cost to non-billable labor

New to Sage, and learning.

So I have been asked to close Job work order's that we did not billed the customer. But in payroll (5-2-2 payroll records) I see that the labor cost was charged to the job. 

How do I change that? I have been asked to change that to non-billable labor, can that be done? Also, this took place 4 months ago too.