how to add firing sounds and muzzleflash?

how to add firing sounds and muzzleflash?

ok i downloaded some of the turret models in the starcraft section but irony is they are unusuable becuase they

1. make no sound when attacking, and since the natural weapon for these models are the rifleman, there is no projectile sound.
2. there is no muzzleflash, like from the marine model (i want to use that one)

i know these things are determined inside the .mdl but how do i add them?

I think you'd manually apply them.
Existing wc3 models should have sounds, but not all other models have them, you'd have to manually add them.