hi,yes you probably just downloaded the skin and extracted the whole thing to skins folder in documents,in the downloaded folder theres 4 diffrent styles to choose from
you need to download the file then extract to a place on your hardrive then go to it and open it up and select stelko x1 folder and copy and paste that folder to user documents/SI/FM11/skins
load up the game untick'use skin cache' and tick 'always reload skin on confirm' selct stelko x1 from the drop down menu and hit confirm