How to get access into an IPhone 6s when you don't remember the password?

A friend of mine says she forgotten her password and her iPhone ID. O_O I don't know **** about the IPhone lol I've only used Samsung and LG. But I have no idea how she would forget something like that… But can anyone help? And if you can't then please do not reply ^^ It'll be much appreciated!

You can't

You don't, it's locked down pretty good. You'll need to do a restore, which sadly will delete all your current stuff from the phone. An iTunes backup will revert to the day of the backup, iCloud will have the sync-able stuff online if you're signed in.

Apple Support: "If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled"
https://support.apple.com/...s/HT204306