Hi! I'm DYING to replace my stair railing. I don't know the first thing about how to go about this. In fact I don't even know if you call this a banister, or balustrade etc so feel free to let me know lol I am looking for something more modern, clean lines. I've attached some inspo photos.

I want it to be done nicely but definitely on a budget.. I don't even know what this will cost me. Should I attempt to DIY, call a contractor - what kind of contractor would it be? Anything you can tell me about how to do this, where to get supplies, or who to call...would be helpful. FYI the carpet is staying so it is just the white and brown wood I want to do something with.