u/Dazzling-Dentist3212

I’ve been experiencing a rattling noise coming from the lower half of the b pillar (I think that’s what it’s called) in my Kia soul. When I’m sitting front passenger it’s super annoying. I want to crack open the lower part but want to know if anyone has any advice? I have the proper tools. Picture added of the part. It’s coming from the lower black part. Something loose.