The axles go into the chunk so you will definetly have to pull the axles to get the chunk out.
No need to pull the nut on the yoke off unless you plan on changing the gears.
Also you will need to pull the brake drums off to get to the 4 bolts that hold your bearing retainers in place on your axles before you can get those axles out, if it's set like a ford 9 inch or Chrysler 8 3/4" rear. Once you get those 4 bolts out of there then you can pull your axles. Try renting an axle puller and a local hardware store to make pulling them easier.