Load a cleared saved game file. You will see a new area at the Van Haven Waste named "Sinca Reincarnation Pilgrimage". If you are level 50, you can go to C3 on the map and talk to "The Usher" to reincarnate. This will bring you down to level 35, but you will have all previously earned skill points. You can then earn more skills and reach level 50 again.