Correcting wrongly posted project cost related asset lines

Hello Everyone,

I am looking for the solution to the below scenarios. 

Case 1)

I have generated asset lines for a project from project expenditures and after interfacing the lines to FA, I realized there is an error in the cost.

what can be done now to correct the costs in projects, as the asset lines have been posted in FA.

Case 2)

another scenario with supplier cost coming from AP. Costs have been transferred from AP to Projects and then to FA, and again asset lines have been posted in FA. Now, if there is an error in AP invoice amount, what can be done so as to correct costs related to asset lines in FA. Also, what would happen to the invoice as all the costs have been posted now and I want to change the AP invoice amount.