How to factory reset my iPhone 6 plus without itunes?

So my friend gave me an old phone of hers to use while mine is being fixed. It was dead when she gave it to me, so when I went home to charge it, it said "iphone disabled, connect to itunes." I asked her for the itunes information so i could factory reset the phone; however, she told me that she did not know it. Is there any way that I can reset this phone without the itunes information?

There's no way to avoid iTunes. Even when you wipe the phone you will need iTunes to retrieve and install the iOS.

Let me be completely blunt here…

THERE ARE NO OTHER OPTIONS TO RESET THE IPHONE ONCE IT STATES "iPhone Disabled, Connect to iTunes"

Even if you set the phone in Recover Mode (on the iPhone 6, you hold down both Home & Power buttons when starting up), it will ask you to connect the iPhone to iTunes (w/ a computer that's online) & will remain in Recovery Mode for 15 minutes (afterwards it disengages, just in case you accidentally triggered this). When connected to a computer with iTunes, it'll detect the iPhone in Recovery Mode & ask if you want to reset it to factory settings. Once you confirm this, your computer will download the latest version of iOS for the phone onto the computer before flushing the phone's storage & reinstalling iOS to return it to original factory settings.

CRITICAL WARNING: Please be aware that performing a factory reset on an iPhone (running iOS 7 or later) WITHOUT REMOVING YOUR APPLE ID beforehand will trigger the activation lock. This is an anti-theft measure designed to prevent anybody EXCEPT the rightful owner (of the associated Apple ID) to utilize the device. When going through the initial set-up & activation (which requires an online connection), Apple will see that an Apple ID is associated with the device & will require that user to log in before you can proceed.

THE ACTIVATION LOCK WILL REMAIN IN PLACE UNTIL THE PROPER CREDENTIALS ARE PROVIDED. APPLE, RESPECTED TECH SUPPORT AGENTS & CELLULAR CUSTOMER SUPPORT AGENTS WILL NOT ASSIST IN BYPASSING THE ACTIVATION LOCK (as it's illegal for them do to so… Mostly in part of DMCA)… EVEN IF YOU CAN PROVE THAT YOU ARE THE ORIGINAL PURCHASER OF THE PHONE!

THEREFORE, IT IS VITALLY IMPORTANT TO REMEMBER YOUR APPLE ID & PASSWORD (OR AT LEAST SET UP ALL ACCOUNT RECOVERY METHODS) TO AVOID PERMANENTLY BRICK YOUR DEVICE.

I know this isn't the answer you want to hear, but it's the extremely harsh truth that you'll have to live with & one that you'll consistently hear.