Iff you whont a quick fix with out takeing the pipes off , 1, get an old long boot sock ,soack it under the water tap , ring it out so its damp . 2, get some Auto'Gleam paint renavater and put a big splodge of it on the middel of the sock, 3, then rap the sock twice arownd the Header ,holding the ends of the Sock and pull it back and forwerds Vigerasley ,this way you will polish it 360'DG , dont let the polish dry out ,keep adding it as you werk your way along the tube length ,
it will onley be tarnishing that will come off and leave a nice finish .
iff its an 06 onwerds you will onley be abule to polish the frunt header eney way , the rear is part of the center linkidge and the rear header is atached to this , as this has some sort of coating on it maybe saramick I dont knoe I woodent try polishing it incase it takes the coating off .