The most difficult bit is lining it up centre. I measured to the middle of mine and put a masking tape strip, then measured into middle or bumper, aligned the two strips and taped the splitter to bumper then screwed it on with 4 screws. I think 4. Might have being 6.
I thought it might be a bit different to not cut down the centre supports and put the holes in the bumper for splitter to fix into like the Cupra R
I quite like how it sits down a bit