There are a couple of methods to load the bags. One is with a spitz lift. The bag can be hung on the frame while you pump/auger product into the bag then simply lower the bag down the hole to your desired depth with the winch. There is also a trapeze system that can be suspended from LV cranes.
In conjunction with one of our customers, we have also developed the KBB lowering device which can be used from a forklift.