I have big hands as well. I took out the belt yesterday to change the old fan clutch to a new one designed for the OM606. I took off the belt without taking out the fan, but backwards was harder. I (and this is where I may be newb) found it easier to take out the fan and do the belt change. Having the belt on before the fan also helped me grip the water pump pulley to retorque the fan clutch.
Don't worry about it. I had a lot of doubts and I have to say after studying this:
R&R of Viscous Coupled Fan, Serpentine Belt Replacement W210 E300D
It was super easy! You can do it!