Remove the brake line from the wheel cylinder. You will of course then have to bleed the brakes afterwards - and yea, have something to catch the fluid upon being released. You might have to remove the emergency brake cable too, probably so. I forget how end play is set on the 8", but there might be shims between the backing plate and the axle tube.  If there are try not and bend them (they are thin) and make sure you put the same ones back on the same side.

If you are going to do that NOW is a good time to replace the fluid. In the absence of a drain plug you need to loosen the..., and choose your name, third member, pumpkin, carrier, center section, rear end. This way if the gasket gets damaged it is easier (actually make that necessary) to replace with the axles out. But, like I stated in the other post if you can siphon it out so much the better and you prevent a number of possibilities from becoming a problem. Not the least of which is getting the smell of gear oil off your body!

Is your axle an 8"?? If it is the lighter duty one, standard with the 4 cyl engines, you need to remove the rear cover as the carrier is integral with the axle.