The easiest way to use is open the Animated Arrows blend file and find the arrows you wish to use. Select the arrow and its parented empty (As well as any curves etc. associated with it) and copy and paste it into your blend file. Use the empty to move the arrow where you need it and check the animation fits with your timeline (correct animation with key frames and shape keys if needed). 

Enjoy the time you saved by not making the arrows yourself!