It will take more than that. The estimates vary in terms of how many CDers there are. Some people think it is 1:100, which may be true if you count the people who have no inclination to do anything other than underdress on occasion, or who genuinely prefer to keep their feminine presentation in the closet since they have no wish to present as a woman in public. I mean, realistically there is a large segment of the CDing population for whom the dressing is more sexual and who solidly want to lead purely male lives. So ... if you look at just the CDers who do want to present as a woman in public (it follows they want to be treated like one), I think the numbers are closer to 1:500 or perhaps fewer. This is not enough to alter society's perception, IMO. And if my numbers are conservative, I don't think even 1:100 is enough.
So, in addition to all these CDs deciding in concert they will dress regularly in public, there would need to be a massive increase in public education in sex ed classes and in the media including more shows that normalize the CDing and also the news, talk shows, and print media that discuss it. This would have to be done on a regular basis and not occasionally, using a sensationalistic approach. At the same time there would need to be changes in all state laws that protect against any discrimination against crossdressers, and also many more companies would need to have sensitivity training sessions for their employees.
I think that should do it, and I do think it is possible. I have no idea how long it would take though.