Tbh its so easy you may as well do it yourself.
When i did mine i was a complete newbie to spray painting. All you have to do is remember to do lots of thin even coats.
Remove the trim from the car, give it a light sand, degrease it with sommet like meths. Do about 4/5 thin coats of primer, leaving 15 mins between each one. Leave for 2 hours if in warm conditons, then give light sand wiht wet wet and dry paper, dry and repeat the process for the paint. At this oint you can either laquer it, just 2 coats of laquer, or just give it a light sand with fine, wet wet and dry paper, then T-cut it till smooth and shiney, then polish up for that showroom finish. personally with the laquer i found that it didnt give an even finish, used it on my trim, but when i repared a scratch froma hedge i didnt use it and it looks fine.