The proposed fix (yet to be approved - note the difference between "proposed" and "approved") is spelled out in the consent decree document.
Yes, you will have to do some digging to find it. So did the rest of us.
No DEF tank. The LNT catalyst will be replaced. No one knows what the difference will be between the old one and the new one. No one knows (and has publicly stated) what the real world effects on fuel consumption and power output and driveability etc is going to be. It is known that after the modifications the vehicle still won't really be compliant in real world driving, just closer than it is now.
