Just did this job yesterday following this DIY. Pump had went out at 58k on my 08 335i AT. This DIY was awesome, very thorough, great pics, each step accurate and easy to follow.
As everyone says, not complex, but almost every step is a bear due to space limitations and everything covered in coolant. Took us about 6.5 hours not including lunch break and some parts runs.
Simple sounding things like removing a hose or setting/removing a spring clip took several attempts each from both myself and my friend, and we are no strangers to working on cars. The angle in which you have to grab these things and the amount of pressure required to separate them is a nightmare lol.
Part of me wondered at times if it would have just been easier to remove part/all of the front end. The time saved by not doing it may not have outweighed how easy that would have made it.