If you need to remove the door sill plate moolding, the factory plastic clips are very brittle and will break. Hopefully the clips give way before your very expensive trim piece! These replacements printed in TPU hold the trim securely but have just enough flex to be removable without damaging the lip on the trim piece.

Print in TPU or similar flexible material. No support needed. The ones in the image are printed with Sainsmart 95A TPU with a 0.25 nozzle and 0.10 layer height.