I don't think you have to. You just need to let everyone know that all cultures have positives and negatives. Also, there are good and bad people in each culture and no person can represent a culture by themselves.

i think when the person who belong to this culture behave well and appear the most good things in his culture .he should be kind and be able to hear any critique about his culture and discuss about this quietly and by logic with smile, then i think people may change their opinion about it :D good luck for you :)