Jerry, I replaced the engine mounts on my W116 and you are on the right track about loosening the big bolt underneath first. You also want to remove the top bolt for the engine shock, but if the bottom is easier for you then go for it. I did both mounts at the same time. It is a pain to get to those allen (hex) head bolts. Really the only thing holding the engine onto the frame is 2 10mm allen head bolts. These you get from underneath. Once you have these out, and disconnected the engine shock, all you need to do is jack the engine up. Be mindful of the radiator fan blades, as they may get caught on the fan shroud. What I did was loosen the fan shroud so that it would go up along with the fan. Also be careful to only jack it up as high as you need, no further. In theory, you could rip the radiator hoses off. I used both a regualr allen head key and a long allen head "T" that I bought from Sears. Mostly you will use the small allen "key". It is time consuming, but the it definetly makes a difference.
I hope I didn't confuse you at all.
1994 MB E320 Coupe (199,500 mi)
1992 MB 190E 2.6 (173,000 mi)
1983 Porsche 911SC (148,000 mi)
2004 Volvo V70 2.5T (198,000 mi)
President of CT/Westchester Section