transaction edit done by mining nodes I'm reading through bitcoin manuals and I got this question, please help me to correct my understanding.

I'm aware that changing the transaction output amount value can make the transaction unusable. What happens if the mining nodes lowers the output value to get more transaction fee, in such scenarios how the bitcoin protocol counterfeit that?

Thank You.
Most transactions contain a digital signature which signs a hash of the transaction. Usually this hash includes the entirety of the transaction, so changing any part of the transaction would invalidate the signature and thus invalidate the entire transaction. The miner won't be able to change the output values you signed, because it would change the hash.