For the large nut you can use lock plyers or channel locks. Yes you are loosening the nut to shorten the driveshaft to pull the drive shaft out of the spline.
Mark the drive shaft for orientation. It is balanced and needs to be reassembled in the correct orientation not 180 degrees out.

Take the whole driveshaft out so you can work on it easier. And mark it for orientation.

You will need a puller for the center bearing.

Check your flex disks while you are there.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car