People were asking how do i convert animations from some games to Skyrim, so I decided to make a short guide. Hope it will be useful for someone.

This guide covers how to transfer animations from one skeleton to another using Motion Builder. It will also cover animation mirroring as a bonus.
This guide won’t teach you how to create and edit animations, won’t teach how to use 3Ds Max or other modelling software, won’t teach how to import/export animations, or create Skyrim mods.

If you want to learn about importing/exporting animations for Skyrim, read Skyrim Animation Tutorialby xp32 and aeon.