Most of the parts stores sell inexpensive hand pumps that work reasonably well. Put the suction line into the container, pump into the tranny/rear end. You can drain them the same way - just reverse the pump; however, I never really trust that I can get the hose to the very bottom of the tranny/rear end to get all the old fluid out. I've also found that certain fluid containers (Mobil 1 gear lube comes to mind) have pointed tips on them. I can usually force a hose over the tip, clamp it on, and then insert the hose in the fill hole, and simply squeeze the bottle with my hands and force fluid in. You can't completely empty the bottle, but most of us keep excess fluids around anyhow as we're frequently changing fluids on something.