oil leaking and sludge build up on 2003 Pontiac Grand Prix

We have been told the car has sludge and is leaking oil, slowly. how do we fix this issue

Asked by for the 2003 Pontiac Grand Prix
The only way to confirm sludge build would be to at least remove the valve covers from the engine - has that be done? As for external oil leaks - The source of the leak will need to be determined and whatever seal or gasket is leaking will need to be replaced. I would not be uncommon for the lower intake manifold gasket to be leaking on your 2003 Pontiac Grand Prix.