Mine is the S1 E51 and ive noticed they have those silly clips too. Had them on my E50 H/W Star also albeit I sussed them out in the end. Trick is to gently twist them until they line up and squared to the holes and then the grill should just pull away ( Gently of course ) post all other top clip removal. Why they cant be just held in place with screws I'll never know.
@Andy G yo is yours the white rider? Looks like you have asetting withmore than 3 led sections trailing, I like it! Is it the same one i have (5050 brand or something)? I didn't notice that setting. Might just be how it looks on the video though.