Reduce Machine Hum in Clip

I’m working with a 15-second movie excerpt that contains nothing but a man’s grunts and a low machine-like hum. I need that hum tamed—just enough so it no longer distracts, yet still leaves a subtle room tone for realism... (Budget: $15 - $20 USD, Jobs: Adobe Audition, Audio Editing, Audio Engineering, Audio Mastering, Audio Production, Audio Services, Music, Sound Design)