How to export custom model with 3d game kit animations applied to it from unity to Blender

I downloaded the 3d game kit character pack and I can see the animation clips with my character on in the preview and I can play the animation clips with a simple animator on my custom character in the scene and it works perfectly. I want to use those animations on my character on blender but I can't, since I tried to import both my model and the animation clip hoping to mix them with the Blender's Dope Sheet ( > Action Editor) but it didn't work.
How can I mix them both in unity and export to blender? Is there a simple way to customize into unity the animation clip and then export or even something to do that on blender?
Thanks in advance for the answer and sorry for my poor english.