are you out of the warranty period already?
BMW has a list of oils that should be used if not using their own brand. You will most likely need to buy your own oil and filter and have them do the labor if you wanted a mechanic to do it, unless you go to a BMW specific shop and they stock BMW approved oil and filters.
changing oil is simple and any mechanic can do it. its just a matter of if they have the required oil and filters. but whatever you do, dont go to those quick lube places.
AW/Terra | ZSP | ZPP | ZCW | iDrive | CA
Mods: BC BR coilovers | Blacklines | M-tech rear | dual exhaust | M3 steering wheel | BMW SSK | ZHP shift knob | High-kick CF spoiler | NBT Retrofit
M3 front control arms | M3 rear guide rods | Manzo rear toe and camber links | Monroe rear shock mounts | Varrstoen ES1 19x9.5+20 Front, 19x11+25 rear