Reigning champions City returned to the top of the domestic table on Saturday after thrashing Aston Villa 5-0 at home a couple of hours before previous leaders Manchester United lost at Norwich City.
However, City's form in Europe has been much less convincing, with Roberto Mancini's side yet to win in four games and facing up to elimination at the group stage for a second season in a row.
City must beat Real and Borussia Dortmund in their last two games, and hope other results fall in their favour, in order to reach the last 16 and Aguero is targeting a win over the Spanish champions by any means possible.
"It's a good game," said Aguero, who scored twice in the win over Villa. "The truth is we have to win so we are going to go out and win however we can.
"We will have to see the other results but in the meantime the important thing is to play how we have been doing and do our best to win."
Another pleasing aspect of the performance for City - whose position was further enhanced by defeat for third-placed Chelsea - was their clean sheet.
The defence, formidable last season, has been under fire this term but they have now shut out opponents in four of their last six league games.
Aguero said: "Scoring goals is good but last season we were champions on goal difference, so it's important that we don't concede and try to score a lot.
"The result I think was very good. We needed to win and now we are calm and in good spirits. With Chelsea having lost their match, we are very happy."