That is correct. The engine shown in that video is not an N62. The engine in my 645Ci has extended mountings on the cylinder head castings. The timing chain guides and timing chain are behind these. It appears that you cannot replace the timing chain components without removing the cylinder heads.

Does anyone know how to get around this problem ????

(sorry, I didn't see the replies above until after I had submitted my post. It looks like they answer my question. Cylinder heads must come off to replace timing chain guides. The pictures in the post by Carl0s do not come out when I view it. What do I need to change to see those pictures ?)