Here is a summary of a valve cover gasket replacement on a 1998 E38, M62 engine. It is a supplement to the TIS and other e38.org links.
Parts needed: 22 ea. of the sealing washers, right and left cover gasket sets, HYLOMAR gasket sealer (Autozone), set of eight spark plugs, several different 10mm sockets and wrenches (incl. offset box wrench), gunk degreaser, rags, dentist pick, and misc. standard tools.
Firstly, gunk and rinse the engine with the acoustic cover off. (Don't use too much water pressure). Then wipe down around the valve covers now and during operations to keep dirt from dropping into the valve train while you are wrestling the cover off.
As known from e38.org and roadfly.com the TIS is primarily accurate but does not mention that the fuel injector connectors have a metal clip that must be released before lifting the cable box out of the way.
As stated in the TIS, I found that it is impossible to remove and replace the covers without the cable boxes being moved. The passenger side is the hardest of the two to unclip the connectors. I used a dentist pick (90 deg. ends). For each connector on the passenger side, carefully lift the end of the wire clip and slide the end about halfway down the side of the connector. This releases both sides. The following photo shows one clip in release position after the box has been moved up and away from the injectors (bottom). The box conveniently rests on the fuel rail.
I did the front three connectors from the top, sort of, and the rear-most one looking from the top of the radiator towards the back of the car. You can't see the rear-most one from most other angles. This part is a real pain. It's like defusing a timebomb. If you slip, that clip goes down into the nether regions of the engine compartment. I found that the clips were well-behaved, though. You'll see what I mean.
There are three other places that interfere with removal of the cover. First, one of the brake lines to the ABS block needs to be held back away so the cover doesn't scrape it too much coming off.
Next, on my car, a fuel line hose clamp at the back of the pass. side interfered with the cover and prevented full removal. To remove the cover I peeled off the old gasket with the cover loose to buy an extra 1/4 inch. To replace the cover, I opened the clamp 2 turns and carefully rotated the clamp ccw to get the screw head out of the way, then retightend two turns.
Finally, as stated in the TIS, the flow meter needs to get out of the way for foward removal of the cover. All you have to do here is unclip the filter box cover and move forward a bit.
Finally, the driver's side requires that you disconnect the battery, and then disconnect the pos. terminal on top of the cover. I found that the driver's side was easier with the cable box cover removed to make more slack for the wire that runs down with the pos battery cable. To remove the cover, carefully pry up all the top and side clips, then rotate the cover gently down to unclip the ones on the bottom. To install, just press on at each clip loc. Also, the driver's side has only three injectors under the cable box. The forth is rearward and has a different clip style (push in at the bottom to release).
I used HYLOMAR blue gasket gunk (from Autozone) at the timing case joints and the corners of the cutouts at the rear.