Co-borrower but not a co-owner

We are four brothers with no sisters. My father co-owns a Flat with my mother as the other co-owner. I am the co-borrower of home loan with my father as the borrower. I have made the down payments and all the EMIs deligently till now. I have proof of it in my bank statements. Now my father wants to will this flat to his other son. how do i get my name removed as co-borrower for future EMIs as the other son is not interested in becoming a co-borrower and also my father not interested in getting my name removed as co-borrower. I can stop the future EMIs but it will spoil my credit ratings for future loans which i dont want. Kindly advise. I read on various websites that, incase of a son not being a co-owner of the property banks cannot make him co-borrower if there are more than one son. He has to be co-owner of the property orl all the sons have to be co-borrowers.