Q: How do I delete off the individual device? I only have 8GB on my Iphone.

Are you using iTunes Match?  If so, the ability to delete tracks seems to have been eliminated (hopefully this will be restored in a future update).  Probably the only solution would be to go to Settings>General>Usage>Music, tap Edit, then tap next to All Music to delete all your music, the re-download the music you still want on your phone from iTunes Match.

If you would like to see the ability to delete iTunes Match songs from your device restored in a future update, you can suggest this to Apple here: http://www.apple.com/feedback/iphone.html.

It is annoying this feature got removed. It seems to be related to the fact that playing songs via iTunes Match does not actually appear to download them automatically anymore? So unless you actually specifically download a song, it just plays it over the air it seems rather than downloading it first.

But since it is possible to manualy download for situations where you might not have WiFi (or 3G) it is a bit annoying you cannot delete the songs except by nuking all of them!

Except that in my experiments, it does still automatically download them.  Streaming only was in the iOS 6 beta, but seems not to have made it to the final release.

randers4, if you delete all your music from the iPhone, how do you indicate which music from iTunes Match that you'd like on the phone?

Make sure in Settings>Music you have Show All Music set to On (so you can see your entire iTunes Match library).  Then to download albums, open Music, tap More, tap Albums, tap the Album you want, then tap the download arrow at the top.  If you only want individual songs, just play them and they will download to your device as they play.