goto xbox.com. Login. Click My Account on the top right. 3rd column from the left is Device Management. Bottom link.
the music on the cloud, or the "cloud collection" as shown on your phone, cannot be managed by windows phone. To add music or manage them, you need the windows 8 app, music. Everything you downloaded on your phone will not be added to your cloud collection, therefore will not show up on your windows rt's music app.So when i download an album on my surface RT, it shows up on my lumia 920 automatically, but when i download on phone, it doesnt show up on my rt in my music app, how do i add my phoen to the managed devices?
There's an option under preferences in the Xbox music app that is disabled by default. Enabling it ought to automatically download any music added to your collection from another device.