I just shipped my launch Joy Cons back to Nintendo for the free repair. They got the drift real hard, so I Googled 'how to' and followed the links which led me to Nintendo Customer Support, and from there I followed the appropriate links to begin the return service, and if you haven't done so yet, I recommend that you do the same. Even if it's not an issue now, it likely will be. Best to take care of it while it's free.
Now from what I gather, I'll be Joy-less (more so, anyway) for about a week and can use my Pro controller in the meantime, so not really a big deal. It has me curious though, have any of you gone through the process, and what was your experience? Got the drift? Get my drift? Share with the class.