First of all you need a modeling tool and [Blender] is freely available.
You also may need the [Ogre conversion tools] (make sure these tools are in your path).
These scripts should be copied into the blender scripts directory.
You may need to install the latest [Python].
And you may have to install some of [Blender’s pre-compiled plugins].
Also you’ll notice when you export the skeleton that the axii are inverted. You can remedy the problem with this:
// Flip axii
Ogre::Vector3 tempPosition = Ogre::Vector3(bonePosition.z, -bonePosition.x, bonePosition.y);