On my 92 400E, the balancer had to come off to get the last bolt out of the waterpump. With the balancer on some of the cars, you could walk it off without having to remove that big bolt in the center. Unfortunately, your picture of your balancer looks just like my 92 400E and I had to take the bolt off to get the balancer off.
If you take the balancer off, you will be disturbing the main crank seal and may want to replace it while you're there. The bolt is a 27 mm bolt that I was able to loosen with a floor jack under a breaker bar (counter-clockwise to loosen). Unless you have a fancy crank lock tool that they use at the dealer, your second option to stop the crank from turning when you try to loosen and tighten the crank bolt is to take out one of the three torque converter bolts and install a long bolt with a sleeve on it to hold the flywheel from turning when you loosen it. In this link I posted a picture of the makeshift crank lock.
http://www.peachparts.com/shopforum/...d.php?t=190442
There is also a special tool that MB has to remove and install the new front crank insert and seal which makes it really easy.