GTA V: Go to your grave in Ludendorff Cemetery
It is a a straight forward drive over to Ludendorff Cemetery. During this time you hear some of the stuff that Michael has held back. Some of the actual talk of the deal that he made with David Norton.
Once you are at the cemetery then you just need to head on through the gate and start for Michael Townley's Grave. Head into the cemetery and go to the far back portion. There you will see Trevor standing in the grave.
The two talk and then Trevor opens the casket up. Everything is opened up.