Sorry to hear that, I made almost the same experience as you. I was lucky to find out by my own, how to disconnect the cables on my A1212 and added a comment to step 17.
ATTENTION for MacBook Pro 17" Model A1212:
If the 2 connectors shown in step 17 are black instead of white: They have to be disconnected by lifting them up, not by sliding them to the left side, as it looks like they would plug off! I used a spudger to go under the 4 cables close to the connector and lifted the cables with the connector gently up. No force needed.
Lorsqu'il en aura reçu, il pourra afficher un graphique de sa réputation au fil du temps.
Voici un aperçu de ce à quoi ressemble ce graphique :
Aucun point de réputation obtenu pour l'instant.