In that video, instead of disconnecting each of the injectors, he explains you can also disconnect one of the battery cables to prevent the ignition from firing.
For the E9x (mine is an E92), the battery is different from the F10 shown in that video.
On my E92, the cable I removed is #3 in this picture:
It unplugs easily:
Perform the priming procedure, then reconnect that cable. On the first try after reconnecting, my engine cranked but actually did not start. Second try, it fired right up.