W204 C350 CDI Injector Replacement
 

Hi All,
New on the forums and I'll apologise in advance for coming on and asking for help straight away :/

Noticed a fuel leak with my '10 C350 CDI the other day, progressively getting worse. Took it into my local garage who managed to track the problem to an injector and return pipe.
The o-ring the return pipe is attaching to was split, he didn't have the correct size o-ring replacement.
He also said that the fuel injector was leaking too and that it would need replaced but he wasn't sure if it was something he could do or if it would need to be 'coded' for the car.

So, a couple of questions -

Where's the best place to buy a replacement injector or should I see about getting this one refurbished (mechanic said that could be an option)?
Will a replacement need to be coded for the car? Do I need to take the car to a Merc Specialist / Indy for this? I'm in Newcastle if there's any recommended one local?

Many thanks in advance!