Have you ever changed spark plugs on a car before?
It is not hugely different than on any car.
BMW does not print official manuals or instructions on this type of service, but here is a great pictoral instruction set for you:
Please let me know if you have further questions, I am happy to answer follow ups. If satisfied with my assistance, please press accept so that I am compensated for my effort. I am not compensated until you press accept.
Actually, I posted the BMW official instructions for removing the ignition coils for you, in case it is helpful beyond the other link I sent you:
You need to click on each file, then click again to download (2 clicks per file).
Let me know if you need anything else.
Please press accept if satisfied.