The timing chain on my W140 (M119 motor, 131000 miles) rattles for a few seconds on the first start after an oil and filter change. There is no noise at all on all other starts, or while the engine is running. In the archives, there is discussion about rolling a new chain in. How is this done exactly, and where do you start? Do you start on the far right hand cam sprocket? Can it be done by one person? Assuming the original chain has no opening link, is there a particlar link that must be undone (drilled, filed away etc) or just any old link can be removed? I would prefer to remove the timing cover and inspect/replace other parts at the same time. If I go this route, does the chain still have to be rolled in, or can it be threaded in with the crank and camshafts stationary? Is part of the head gasket sandwiched between the timing cover and the cylinder head, or is there a separate gasket between them? Does the oil pan have to come out?

I need all the help I can get.

Thanks for your help.