It's much easier to just replace the plastic lenses. You can get them on ebay for $50-$60 shipped. You won't be able to clean the old lenses, it's just discolored plastic.
As for installation, it's very easy, just undo the clips around the headlight housing and everything snaps back together nicely. Just did mine in 20 minutes, if you need help Youtube a DIY video there are plenty of them floating around.