No, it’s not too late and it’s fairly easy. Get a kit at Walmart, there are so many now but the Meguiars kit is nice. Make sure you buy the one with a foam pad that attaches to your drill. Try to polish off the oxidation with the polish provided first - if you run out of the included polish use Mothers Mag Wheel polish if you have it or any other good gentle polish. If that won’t remove the oxidation you will need to sand them first and then polish again. They include the sandpaper in the kit (I think). BTW There are tons of videos on this subject on YouTube. Deep Woods Off with DEET will literally wipe the oxidation off, but it is melting the plastic so it sort of scares me, I’ve never tried it.
Once they are clear again apply the spray coating, which comes off with just alcohol so it only lasts maybe 4-5 months. Don‘t use clear spray paint! A longer lasting protection is the 3M plastic protective film, you can get it on Amazon, or find a window tint place to do it for you.