How to restore my iPhone 3GS?

It says "iPhone is disabled, connect to iTunes" and "Activation required." Its my sisters old phone and we don't remember the passcode, so I can't connect it to iTunes without knowing the lockcode. Its so frustrating! How can I reset it without knowing the code and without being able to connect it to iTunes? If you have any more questions, I'll be happy to answer them. Thanks!

Added (1). Everytime I plug it into itunes it says it can't connect with my phone because I need to enter the lockcode first!

You don't need to know the password to connect it to iTunes. Plug one end of the charger into your phone and other into your laptop/computer and then as usual, when you click to look at the details of the phone (like how much space songs, apps etc are taking up) it says restore. It will still work

You should search Google and follow the guide.

Hold the sleep button on top of the iPhone for 15secs then hold the home button for 10sec and it will send you to recovery mode but everything will be lost unless you ha backed up your memory…

Go on itunes

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