my Uncle prepared a document in that he forged my father and my brothe

In 1998 we shared our property to our share we got part of our house and some land .in 2002 we purchased the other part of the house from my second uncle. My first uncle prepared one document in that he rote half of our house is donated to him. He forged my father and my brother signature. Now we want to demolish the house and want to reconstruct it give me some legislative advice how we have to proceed we have all the evidence with us