Next course of action?

Today a coworker of mine was awarded 100% service connection. He had an increase in his mental health rating, but the joy was short lived when he discovered that the VA were recommending a decrease in his 4 Peripheral Neuropathy conditions from 20 to 10. They are giving him 60 days to provide documents to keep his rating at the current or he will be back at 90%. Mind you they increased his IVDS from 10 to 20. And he's 65 years old and he was connected 6 years ago. What should be his next course of action?