Below is the info from the SIB related to priming the system. I know it doesn't answer your question, but it gives direction to split the 30 second dry crank into 3 sessions. Probably valuable info.
https://www.e90post.com/forums/showp...66&postcount=3
I could be wrong, I've never done it myself, but I think you can just unplug the electrical connections directly from the injectors; Carefully with a flat head screwdriver to pry the clip up. Third photo in the below post:
https://www.e90post.com/forums/showthread.php?t=651538