running boards cleaning
 

How do i clean my aluminium running boards, there are little black spotts in it

Mothers aluminum polish, you might have to remove the naps (the black rubber things) to get a perfect finish, try waxing them after to repel the dirt for next time :)

and how do i remove the naps ?

They pry up and out, either use a flat head screwdriver carefully or some kind of plastic pry tool maybe. Its a little bit of work but well worth it after they are cleaned and sealed. Oh the black strip that runs along the running board should be removed also it just snaps off and on easily. Good luck :)

I use Duragloss MCB (Metal Cleaner & Brightener) and have not needed to remove my naps.