For anyone contemplating a DIY replacement of the high pressure fuel pump on the 328d with N47 engine, here is a walkthrough of the steps involved. I may have left some things out, but this should give you a pretty good idea of what's involved. Having done it once, I would say you could complete this in a long day, but I would probably set aside a weekend in case things don't go smoothly.
So, first step is to disconnect your Mass Air Meter
Then, release the flat head screw that holds it to the airbox
Then, disconnect the pipe from the bottom of the airbox by pinching it and move it out of the way
This gives you access to the lower hose connected to the turbo. Remove the 10mm bolt which holds it in place and the electrical connector on the PCV valve, I have a catch can installed so I have some extra hoses and didn't need to disconnect it from the pipe. Stock would have a corrugated tube here which also would need to be disconnected from the manifold.
Then there's a snap clip that holds the pipe to the turbo. It can be removed by prying to the left by hand, or with a small screwdriver.
Then remove the snap clip that holds the pipe to the turbo
This gives you access to the crank pulley / damper. There's a cap that covers the bolts, gently pry that off with a screwdriver to get access.
I Didn't take any pictures of this task but remove all 3 of the plastic covers from the bottom of the car. There's quite a few 8mm bolts down there, a couple 10mm bolts that require a deep well socket, and a couple anti-theft torx head bolts. If you're attempting pump replacement you've probably removed these before for something.
Again, no pictures but after that remove the heavy metal cover that is underneath the engine, which is held in place with 13mm bolts.
Now that all of the covers are out of the way, on the passenger side of the engine, there is a plastic plug that covers the flywheel port, grab that with a needle nose and pull it out.
This is the flywheel locking key. You can see that the tip has a reduced diameter, this slides into a notch in the flywheel which is only accessible when the #1 piston is at TDC (top dead center) on the firing stroke.
This is the tool for turning the crankshaft. It has indents to go over the 4 bolts that mount the crankshaft.
