Also, the hex-head of that bolt was worn off or something - I assume it fitted an 8mm spanner once, but that was too big now and a 7mm spanner too big, this I had to sacrifice a 7mm spanner and transform it with a file into a 7.5mm spanner... That way I got it off. Also it was way too long - a real torture to get it off. I got myself a shorter M6x1mm bolt to suit a 10mm spanner (small picture).