Stop an animation through Xcode.

Hello, I am creating an animating 3D object in Unity and then importing it in my AR(vuforia) application in Xcode5. On button click inside application, I need the animation to stop and restart on next button click.
Please help as I am new to this platform and need help urgently.

http://alexanderwong.me/post/29949258838/building-a-ios-unity-uiview-uiviewcontroller
follow this tutorial