How to unlock an iPhone 6 without a passcode?

My friend changed my passcode on my phone last night and can't remember what it was and we can't get into it. Without using iTunes because I hadnt plugged it in and synced it up yet, how can I bypass the passcode?

The passcode can't be bypassed by the general consumers.

Your only option is to follow the factory reset options or take it to an Apple store.

Consider in future not letting friends know your current passcode.