You need some real efforts to do so, including desoldering and soldering NAND Flash chips to load iOS 10. Even so, there is an Apple iOS activation server you need to get around. Not to mention any issues you will likely run into by doing so.
If you really want iOS 10, buy iPhone 5/5c, iPad 4 or even iPod 5th Gen. Those are devices you can have that can certainly run iOS 10.