You could purchase those silver bumper trim pieces brand new and get a big enough plastic storage bin as a container and soak them in muriatic acid and it would strip off the silver/chrome coating and leave you with a bare plastic piece ready to prep and paint.
If you’re going to spend the coin to have these pieces professionally prepped and paint matched might as well spend the money to get them wrapped in some paint protection film.
Cause if you’re matte plastic trim looks like this imagine how much more obvious this would be if painted to gloss black to match.
I’m not trying to discourage you here; I’ve done chrome deletes with either painted to match or gloss black with all OEM parts on (2) K2XX SUVS and now on my GMT900.
If you’re using OEM parts then do it once and do it right.
You want to redo it better the second time; That’s what vinyl is for.