You're in luck
A couple of months ago I fixed this very issue on my 2005 4.4 with 140k miles, so every little detail is still fresh in my mind. Here's the thread that I added my experience to:
https://xoutpost.com/bmw-sav-forums/...-seals-12.html Go through it - lots of info in there.
Please have no fear
But I understand coz I had the same thing - fear of the unknown as already pointed out. YOU CAN DO IT! To put things in perspective, I'm just an avid DIY'er and a software engineer by training, who happens to just like wrenching in my garage on my back, as a way of relaxing after being all day in the digital world gymastics
If you decide to pull the trigger, let me know. I still have every single tool you'll ever need for this task, and you can borrow them - serious.