So I took a chance on €40 and bought an LCI F10 M5 service manual from eManualOnline.
Turns out the thing is over 22GB and works through a virtual machine program.
Some great info to have is in there, but now I'm halfway through the job, my experience of the BMW technician instructions is meh at best.
It leaves a load of stuff out, instructs one to do unnecessary things, and says a heap of special tools are required.
https://ibb.co/XXdq6JH
Anyway assuming this job goes OK, I will post up all the pics & videos I'm taking along the way to make a DIY/how-to thread out of this.