How do you propose to do this?
On a personal level, I can say I do it already. For instance, when a person uses the Swastika as a Nazi symbol, I choose to interpret it as a Hindu symbol until he specifies that he meant it to be a Nazi symbol. I can also choose not to use the Swastika myself, especially as a Nazi symbol.
On a wider scale, of course many more people would have to do the same. But let's suppose it were done. It wouldn't take long for a Nazi to feel a little awkward when people, seeing his Swastika, ask him when he'd converted to the Hindu Faith, or comment that he looks very different from other Hindus they know. Seeing that non-Nazis far outnumber Nazis, if non-Nazis chose to abandon the Swastika as a Nazi symbol on a large scale, Nazis would either have to separate themselves even further from mainstream culture than they are now, or abandon the Swastika as a Nazi symbol themselves, thus forcing them to redifine themselves. And seeing how fragile their identity is to begin with, it would likely cause a certain cultural turmoil within the Nazi movement for years or even decades to come as they debate, first off, whether to even keep the Swastika at all and, if not, then to determine its replacement smbol.
Add to this that a dissociation of the Swastika from Nazism would likely make Hindus, Buddhists, and Jains feel more comfortable sporting it themselves, thus helping to separate it even further.
This would also mean a change of attitude in schools, meaning that schools likewise would no longer impose a Nazi meaning to the Swastika.
It would essentially return the Swastika to its original roots while marginalizing Nazi ideas even more than they are now.
We can add that some First Nations also use the Swastika as a symbol, as did many Americans, Britons, and Canadians in the past as a good luck charm.
most educated people know its dual meanings and don't freak out. It's pretty hard to reach those who choose not be educated though.
Now I do see a problem there. If I were a Hindu, for example, I could insist on sporting a Swastika myself precisely with the intent of dissociating it from Nazi ideology. Seeing though that I am neither Hindu, Buddhist, nor Jain, nor do I believe it to be a good luck charm, nor do I identify with the Swastika i any way myself, I'd see no reason for me to wear a Swastika even if Nazism had never come into being. Looking at it that way, those who do associate with the Swastika in any way bear the primary responsibility to dissociate the Swastika from Nazism shoudl they wish to do so. However, I could see myself serving in a support role of sorts by defending the right of a Hindu, for example, to wear the Swastika, while refusing to acknowledge Nazi uses of it.
But you are right that it would be pretty hard for me at least owing to my not having any association with the Swastika myself except in popular culture.