And while others release the tension of the tensioner (when installing the new drive belt) from underneath, I did it from the top, making my "special tool" even more special: After pulling the ratchet via the pipe extension up, I stuck a huge screwdriver into that pipe to arrest the tensioned in that position, which allowed me to very comfortably and slowly bring the drive belt into position (the correct position after 1 failed attempt in the wrong position (see top of thread).