How to deauthorize an iPhone without iTunes? I no longer wish to use my old iPhone 3GS. 
I used to use my Apple-ID to log into The iTunes &amp; App Store on it.

Since I use that Apple-ID for iTunes &amp; App Store on several other iDevices, I want to completely deauthorize and unregister the iPhone 3GS from my Apple-ID.

I have already signed out of iTunes &amp; App Store on it. Can and should I "deauthorize" it in any other way?

I no longer use the iTunes program on any computer, so the iPhone is not connected or synced to any computer of mine . (And I don't want to install iTunes, I don't like the program).
You should explicitly deauthorize it. The standard way is to use iTunes.

But if you do not want to install or use iTunes, you can get Apple Support to help you:


Go to the Apple iTunes Support page
Click on the Contact iTunes Store support link (click OK when it prompts you about redirecting you to another page)
This currently takes you to the What's happening with iTunes? page
Click the Account Management box to open up further options
Click the iTunes authorization or de-authorization link
Choose how you would like help - the current options are for Apple to call you or to schedule a call back from Apple or email Apple Support
Provide the details of the Apple ID and the device in the request for deauthorization