cfbr,
Not A lawer.
it might not be possible, as your uncle has partial ownership (not complete) hence can’t sell entire house (or use it as colatrall in bank). unless other uncles were tricked to be co signers of the loan you may have a solid case againt bank.
go through loan documents and check if they have considered entire house as colateral.
consoult a lawer, have a conversation with bank manager.