回复：I talked to my friend and he does not want to work for others

just for GC. He said he can pay himself as self-employed but don't know whether this is good enough to reopen the case.
-Two important things: 1. His current job for himself is the same/similar area as that indicated in the previous I-140. 2. He may need to provide the evidence that his company can pay himself such as the tax return, etc.

Then he should have no problem to win the MTR.