How to re-orient a skeletal mesh in Maya

I am attempting to re-orient the skeletal mesh for the assault rifle from the Epic Shooter Game demo, as I am using it in one of my projects as a mock asset and it doesn’t align with the rest of the weapon skeletal meshes I use.

I have exported it from UE4 as an FBX file, and opened it in Maya, but so far, I’m a little lost (I’m a programmer, and don’t know maya well). I’ve discovered that the FBX exporter creates an extra root bone which must be removed apparently. I know how to do that (right click -> actions -> unparent, and then delete the root node), but the meshes are misaligned and the controls appear to be locked out.

I’m also not 100% sure I’m doing the export correctly, as when I re-imported, the gun is aligned to the UE4 Z axis. I read somewhere that instead of changing the axis in Maya, I should set the up axis to Y during the FBX import in UE, but I don’t see that option.

Any help would be appreciated.

Screenshot:

Update: I can now reimport it appropriately, and the skeleton seems correct, but no orientation changes seem to take effect

This turned out to be far simpler to do via blueprint (set relative rotation).