I've heard lots of things over the years, different color compounds and buffing it with wheels etc, but I don't know if any really work.  Chrome is hard and thin, so you can do  more damage fixing it thean just leaving it alone and living with it.  If you'ld like to try anyway you could look at this link:
areallygoodname.com/2007/07/11/how-to-polish-chrome-and-remove-exhaust-scratches/

I don.t think there is much that will get scraches out of chrome.......

One thing I have learnt the hard way is to be very carefull where ya place polishing rag etc...

At some stage I must have put some rag on the work bench where there may have been some metal filings, used it later on some chrome and bingo fine scratches that annoy the shit out of me I now keep rags well away from potential contamination....

Bt