Bayern will host the double defending European champions at the Allianz Arena in next Wednesday’s first leg before heading to Madrid for the return on 1 May.
The German champions have painful memories of Ronaldo, who scored five of the six goals that scuppered Bayern’s Champions League challenge at the quarter-final stage last season.
James is hopeful Jupp Heynckes’ men can do what no Champions League opponent has done so far this season and shackle the prolific Portugal international, who has scored in every single match in the competition to date.
"Ronaldo is a goal machine, he has proven that more than once. The numbers speak for themselves. I hope we have a good day and defend well against him so that he’s not so good in the two games against us," the Colombia midfielder, who is in the first season of a two-year loan from Madrid, told AS.
"But Real isn’t only Cristiano. They have great players in every position. It won’t be easy."
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Though they slipped up against the Spanish giants last term, Bayern do have happier memories of meeting Madrid in a European semi-final, beating Real on penalties in the 2011/12 season.
Given their imperious Bundesliga form, which has seen them already wrap up the title, and the fact Madrid are languishing in third place, 15 points behind leaders Barcelona, Bayern head into the game as slight favourites.
James, however, is aware that Madrid always save something special for European competition.
"In the Champions League, they always step up in comparison to the league, and they always manage to get the best out of themselves," explained the 26-year-old, who added he will have no room for sentiment against some familiar faces.
"Both games will be special for me. I was at Real for three years, I have friends there and good memories from that time.
"I’m only thinking about my team now and how we can beat Real. I want to help my team with my qualities and contribute to taking us to [the final in] Kiev."