I need to replace the starter. Is it hard or easy to replace? on 1991 Mercedes-Benz 560SEL

Power provide directly to the starter verified it is dead. Do I need to drop the transmission a bit or play with idler arms etc. or is it a straight forward fix with some 10mm bolts?

Asked by for the 1991 Mercedes-Benz 560SEL
it should be straightforward since it takes only a couple of hours