Sorry to say, but if a lens becomes scratched, you are pretty much out of luck. People think that you can buff it out, but that would only damage the lenses more on majority of cases as there are usually a coating of some kind on the lens.
Any lens scratches, even if it has a scratch resistant coating, lots of people think when they have a scratch resistant coating that it is scratch proof, which is not the case, like the coating says, scratch "resistant", not scratch proof. So it'll be harder to scratch the lenses, but it can still happen.
There are many articles online about removing scratches, but they may only help with minor scuffs. And if the methods do work, if you have a coating on the lens, most of those methods will ruin your coating. So try them at your own risk.
