Upgrading to Windows 10 is a little trickier, especially now that the free trial of Windows 10 has ended. However, it is still pretty straight forward. The only difference between what you could have done a year ago when Windows 10 came out and what can do now is that you need to pay for the software. You can do this by going right to the Windows site and purchasing it online.
This allows you to download the software. Then, all you have to do is follow the on-screen instructions to install it. This is really all you have to do for the Windows 10 upgrade, but it all comes down to if you want to pay for it or not.