So first of all to get Windows 10 on your Desktop, laptop or your mobile devices you will have to become a Windows Insider. Becoming one is pretty easy though. Just head over to the https://insider.windows.com/ and sign in with your Microsoft Account. That will tie ur Microsoft Account to Windows Insider.
Now over to the second part, getting the Preview software..
Remember this is still under development and it might have a lot of bugs and apps might crash and not work. Install this at your own risk. Also the Windows 10 Mobile might not be compatible with all Windows Phone devices right now so make sure to check this list and see if the one you have made the cut.
Before you move forward please read this first to make sure its right for you.
Okay now that you are completely ready, lets get the update…
FOR PC USERS : Download the Technical Preview July Update ISO(3GB+) here.
FOR MOBILE USERS : Get this Windows Insider app from the store. Sign in to the app and choose whether you want to be a Fast or a Slow Ring user. Slow ring users are usually guaranteed a much more stable build than the one Fast Ring users get. Your phone will reboot.
When that is done head over to Settings> Phone Update>Check for Updates and download and install a new update
IT TAKES A LOT OF TIME SO MAKE SURE YOU HAVE A LOT OF BATTERY LEFT OR JUST LEAVE IT PLUGGED IN TO A POWER SOURCE.
Still have questions? Ask me in the comments below.