Sergio Aguero scored twice, with Leroy Sane, Raheem Sterling, Bernardo Silva, Phil Foden and Gabriel Jesus also on target.
Guardiola said, “It was a clear result. We are happy to get to the quarter-finals. We didn’t start that well, we were a bit scared to play. But after it went 1-0, we relaxed and decided to play and be aggressive.
“Of course with the qualification already secured, it was tough for them and we kept a good level. We have a lot of injured players so we want to continue this run and get those players back fit.
“Everyone has to compete with each other to play. They all want to play. Everybody tried to play, be bold and keep going.
On the use of VAR, he added: “They need to be a little bit quicker to make decisions but it is fair. The two penalties went against us from VAR in Germany but at the end it is fair. At the end that is what we are looking for. Hopefully in the Premier League next season that is what can happen. I am happy with VAR. Hopefully it can be quicker than today.
“I like the teams who deserve to win, go through. Sometimes you don’t go through for wrong decisions. It helps referees to make those decisions fairly.”