How do I flip a MSH?

I’ve replaced the default mesh on a drop projectile (i.e. Sky Shard) with the mesh of a hammer. It drops from the sky handle first. I’d like to reverse this so that the head of the hammer is falling first. Any ideas on how to do this?

I’m guessing if I had 3DS Max or something similar I could edit the MSH file but I’m sure there’s an easier way.