How to change the pitch of an mp3 file?

I’ve gone ahead and recorded some audio through my mic, but now I’m looking to shift my vocal tone. I want to mask my natural voice so nobody realizes it's actually me speaking. I've heard there are specific software tools designed for this kind of thing.
Does anyone know a professional who could handle this with high quality?

Any DAW you can think of.

So, can you recommend someone who could actually pull this off?
I just really don't want it sounding like some mindless robot or Microsoft

So, I just finished installing "AV voice changer diamond 7" today. But I'm having a bit of a struggle figuring out how to actually change the pitch or tone in an audio file I've already recorded via my mic.
Does anyone happen to know how this works? Could someone walk me through it?