How can I remove the scuffs and abrasions from the Cold Steel training weapons (i.e. bokken, wakizashi, etc.)?

The Cold Steel training weapons are made of high grade polypropylene and can really take a lot of heavy hits in spars without any structural damage. However there are occasionally some scuffs and abrasions after many fights. So how would I go about removing these surface marks? An in depth answer would help.