To whom it may concern. I tried this procedure as it seemed to be the easier one.
I followed
this procedure and it all looked well:
However when flashing started the flash was really slow, first sequence took more than 30 minutes. The first flashing sequence went ok and then the second flash sequence didn't start and I got some errors.
The car did start but could not engage in any gear, it just sat there in Park. So it seemed to be bricked. I was really scared at that moment.
Luckily one of the forum members here was kind enough to help me out. One hour after I contacted
cn555ic we were having a teamviewer session and he solved my problem and unbricked my TCU and flashed the alpine software correctly. The actual flashing indeed took about 4 to 5 minites.
So many thx to
cn555ic 
, he really saved my day. Sofar really enjoying the car with the new flash.