Hein,
Attached are four files which show the drawings and parts lists for the cooling system and timing chain system.
The plastic top guide that you mentioned is open on the back side and does not fully enclose the chain. I think all of the other parts you mentioned are pictured in the drawings and have corresponding part numbers on the parts lists.
The "bolts" that you mentioned are probably the internally threaded pins. Is this correct? If that is what you meant, there is a puller tool to pull those out. I believe it is threaded 6mm x 1 (not 100% certain of thread). You can also make a puller out of an appropriately threaded bolt a socket and some washers. put the bolt through a few washers that are larger diameter than the socket opening, pass the bolt through the socket (used as a spacer and bearing surface for your improvised puller) and thread the bolt into the exposed end of the internally threaded pins (#83 and #86 on the timing system parts drawing attached). Tightening the bolt pulls the pins from the block and frees the chain guide.
As for the coolant pipe with O-ring at the left rear of the cylinder head (pipe is #179 on the coolant system drawing), I did disconnect the flexible hose attached to it. As I recall, I think I wiggled the rigid pipe out of the head after the head was removed from the block.
I highly recommend that you sign up at this URL for the FREE subscription to all of the parts drawings and part number listings for any Mercedes that you own. It has been a great help to me
EPC-net Online
The information is VIN number specific and you enter the VIN(s) when you register.
Happy to help so don't hesitate to ask any questions that may come up.
Ken