I had to replace the door lock actuator on my 2008 BMW 335i Sedan. There is a procedure, such as checking Fuses 56 and 57 (see https://www.e90post.com/forums/showthread.php?t=477507) before committing to new actuators.

I got this from a vendor named "Mueller Motorwerks" on Amazon years ago (they confirmed the correct part number using my VIN, they don't seem to be around now): https://www.amazon.com/BMW-Actuator-Mechanism-Genuine-OE/dp/B00KHB28NO.

I replaced it on my driver's side. I even bought some trim pry tools. But when the passenger side failed, I just had the dealer install my part for me. (I ordered the pair early on.)