The front black part, is that alpha-editable?
Nope
But here is a recolor that gives you the possibility remove parts by blanking them out on the texture file.
I removed the front part on the texture file.
However, i have no idea how it looks ingame and its even possible the helmet gets invisible on some angles.
Also the reflection will prolly be gone, not sure...
Just try it, its the best i can do.