How do I unlock the gyroscope on my I phone 5?

What are you trying to do that you say the gyroscope is locked? Are you just trying to change the screen orientation from portrait to landscape? That can only be done in some applications, however it is possible that you have orientation lock activated. Check the status bar and see if you see an icon close to the battery icon that looks like a lock with a circular arrow around it. If so, that is what it is. To toggle this on/off, swipe upwards from the bottom of the screen to activate the control center. The orientation lock is the last icon on the right of the top row. Tap on, tap off. White is on, black is off.