I followed the guide step by step and had some pieces of paper with step-numbers on it to arrange the screws. Messing around with my Mac always makes me nervous but this guide pulled me through.
My MacBook went black whenever I moved the lid up or down slightly. Considering the rather poor viewing angle of the display, that happened quite often. I just took it apart; pressed everything firmly while reassembling the machine and now I can move the lid without the screen going black. Excellent !
Thanks a million for the walkthrough !