I have a 2011 i30 CW, the roof garnish might be different, but I believe they all have the same clips.
Please refer to the photo, there are two clips under this trim. marked out in the pic.
Best to start from the one close to the windscreen, insert clip remover into the small gap (red line in the pic) and try to pry up, and others counld be removed in the same way.
There might be 5-6 clips under each trim, and those are quite strong, I didn't break any of those while pry them.
But the real pain is that this kind of vinyl/rubber wrap might not be fully fixed by just using vinyl spray paint, since there are additional water-blocking strips on both sides, they are integrated as one piece with the wrap.
The price to change them could be around NZD500.