upgraded my g5 pro and cant authorize it im at my limit of 5 computers but only use two

Use the Deauthorize All command documented inthis article, or if it isn't an option, the 'contact iTunes Store support' link at the bottom of it.

(131684)

Open iTunes on your computer and click on View>View Account. Once you have signed into your account profile you should see the option to Deauthorize All Computers.

Cheers,

GB