You can download Dynamics AX 7 RTW update 1 from Microsoft connect with following link.
https://connect.microsoft.com/site1321/Downloads/DownloadDetails.aspx?DownloadID=61368
More interestingly, now You can download it in browser, I used Internet download manager.
You can find detail about what’s new in update 1 in following links
https://ax.help.dynamics.com/en/wiki/whats-new-or-changed-in-dynamics-ax-7/
https://blogs.msdn.microsoft.com/lcs/2016/05/27/may-2016-release-notes/