Multiple roots problem with blender

I have a rigged dragon that’s really easy to animate with its ik handles but when I try to import it to ue4 I get an error because it has multiple roots. I’m trying to find a way of fixing this without losing the rig. I’m still pretty new to blender, here is the blendswap file, any help would be much appreciated, thx. http://www.blendswap.com/blends/view/46522