I could not get the ribbon cable out with a pair of tweezers. Instead I inserted a needle below the cable, and gently pulled it out by pressing with the finger on the cable (and against the needle). Very difficult!

I completely agree with Ha ns' comment. I really cannot understand how the author managed to open this device as described. There must be something like a 0.1mm gap between the housing and the cover, impossible to enter a spudger or pry tool. Use a lever on the hinged side of the clip to lift the cover, insert a 0.2mm plastic film or a thin plectrum or spudger on the bent center of the cover. Avoid to push the spudger down, as there are electronic components underneath, only lift the cover, without overbending. Move over to the side of the on/off switch, and release the 3 clips. On the other end an 8mm long nose will avoid lifting off the cover. You will have to slide it out horizontally. Clearly: you have to be very very careful and gifted...

But you have to remove this screw, otherwise the holder will be damaged when rotating the bevel in step 7!

Hi nobody3313... yes you are right, it's not that easy to understand. Actually, the small spring I'm speaking about cannot be seen on the picture. It's a small spring with 3 windings and 2 legs in a V-shape. I can send a photograph, if necessary. You insert the two legs (ends) into the short trimmer, and the winding into the cast part (silver). HTH!