It was the same Fauji general that unconstitutionally kicked out Nawaz in the first place. The NRO merely rectified that unconstitutional action by returning all political players back to Pakistan..
You've complained about vote rigging by the political parties, again, that is not the Army's mess to clean up and neither is the Army capable of cleaning it up.
The problem is that the protests are against the Army - if these protesters are genuine and want to protest injustice & corruption, then they need to protest against local governments, provincial governments and the federal government.
The Army cannot reform the judiciary, police and bureaucracy - only the elected governments at local, provincial and federal level can.
Imran Khan vs Pakistan: Protest of Treachery - Casualty Report
