I purchased a home in Ohio 2003 and established a Life Estate (General Warranty Deed) with my mother as the grantee. She is now living in a nursing home with Alzheimers. Can I remove her as grantee? And how do I do this?
I am trying to refinance my home and cannot as the Life estate is a barrier. My brother has POA... can he assist?

You cannot extinguish her life estate without her consent. And, if she is now mentally incompetent, she cannot give such consent.

Was your brother's POA created when your mother still had her mental faculties? If so, and if it is a durable POA, he may indeed be able to help you.