Interior trim change on E90 questions

Hi Guys,

maybe there is already a thread out there covering this topic. If so i would appreciate being pointed in that direction.

I have three questions:
1) How easy is is to change the interior trim on these cars, for example from a wood grain finish to the silver trim?
2) How readily accessible/available are these silver trim panels in the market?
3) How costly is it? (considering option of new from stealer, second hand from a scrappy, ebay?)

Thanks in advance.