Creating member is usually done by populating the Member Staging Table (tblStgMember), during this process you assign a value for member code and member name. Now if you want to update the member name attribute you can do this by adding record in Attribute staging table (tblStgMemberAttribute) with Attribute Name = "Name". If you try populating the tblStgMember table it will say that the member code already exists.

INSERT INTO mdm.tblStgMemberAttribute (ModelName, EntityName, MemberType_ID, MemberCode, AttributeName, AttributeValue) VALUES

(N'Product', N'Product', 1, N'BK-M101', N'Name',N'Updated Member Name Description')