Complex sentence: The Governor-General has the power to dismiss any member of the Executive Council, but that is not exercised in practice--although, it might be exercised, if hypothetically a former minister was convicted of a serious criminal offence.
Split into simpler sentences: The Governor-General has the power to dismiss any member of the Executive Council, but that power is rarely exercised in practice. It might be exercised, if hypothetically a former minister was convicted of a serious criminal offence.