I found easier opening up the plastic mantle arounding the wires. I was able to put back wires and opened plastic mantle in the plastic stopper.
I drilled it.
For removing the white plastic, I used a little metal saw.
I did not cut the wires at step 7. For having longer wire ends, I cut them after step 8.
I opened only three sides of the adapter.
When re-plugging the yellow connector (the leftmost of the 3 connectors that you disconnected from the top) put the cables behind and not before the metal part with a hole where the EMI Shield 2 clips in. Otherwise you will not be able do step 13.