Unless you find an apple authorized repair shop that's willing to do the install. But you'd probably want to take it only there should you have any problems requiring applecare, and make sure you kept the install receipt.
And a couple of long term 3rd party shops had to close after the apple store finally came to town. I'd hate for the one who would do the upgrade to shutter its windows eight or nine months later. May wait and let some braver souls try it first and see how it turns out for them. After listening to my grandparents tell their stories about homesteading on the frontier, I've determined that I don't want to be a pioneer if I don't have to be.