Refresh devices in team provisioning profile managed by Xcode 7?

It used to be that hitting the refresh arrow/loop button in preferences -> account would pull down a new provisioning profile with all ur new devices.

Now it just downloads the ones you already have. But if the one you need updated is managed by Xcode, theres's no way I can find to add a device to it!

Here's what worked for me on Xcode 8 & 9.

1. Add your device to developer.apple.com.
2. Go to your target's General tab and tap the (i) next to "Xcode Managed Profile", then drag the profile file icon in that popover to your desktop to get the filename of the provisioning profile.
3. Go to ~/Library/MobileDevice/Provisioning Profiles and delete the provisioning profile with the same filename that you got in #2.
4. Xcode should regenerate the profile for your app with the device added in #1.

My account on developer.apple.com was not showing any Xcode managed profiles so this was the only way to make it work.

Simplest way:

Remove the mobileprovision file using terminal

rm + drag the file path from xcode