How to undisable IPhone 5c?

Ok so, my friend asked me to try to undisable her iPhone 5c, since i did it with my old iPod Touch 4 2 Years ago( I'm a freshman in high school), whenever I go into iTunes it tells me allow access from the phone but it's disabled, so I looked it up, yet I can't restart it for some reason, I tried powering off and on again but that doesn't work, any advice?

IPhone 5c is outdated idiot

If it has been disabled due to iCloud Activation Lock then there's nothing you or anyone else can do to defeat it.

If it's been disabled due to having the IMEI blacklisted then that's also irreversible without resorting to illegal methods which require special tools and skills.

That's the entire point.