How to remove residue from the front panel?

I just got an iPod Classic off my dad after coercing him to move all his 4,000+ songs onto his iPhone because he never used this iPod anymore. I successfully installed the Rockbox firmware onto the iPod (new guide on it’s way!) too, not that it matters.

After all of that nonsense, I then noticed the abrasions and the grime that was on the front panel and was wondering how to get it off safely.

What should I use to clean this residue off that is safe to use with electronics? I don’t feel like experimenting with concoctions on this nice iPod… thought that I would seek professional advice.