The rubber hose and funnel method will waste up to a quart. The location to fill the front differential is awkward, having changed the fluid on a Bravada three times and a S10. I discovered the easiest method was simply a funnel, clear plastic tube, a drip pan and a extra quart of gear oil.
My method is easy, slow and smooth. YMMV.
The device you are displacing likely does not have a long enough hose to reach the fill point.