Answer:
For the GE "Compactall" compactors with the round trash bin:
Open the compactor door and look down at the top of the plastic bin. You will see a round silver "retaining ring" with a latch on it and a folding handle.
To remove the plastic compacting bin, lift the handle up and pull the bin up until it stops. Then pull straight out, toward you.
Flip the latch open and remove the ring. You can lay it aside and now pull the trash bag out of the bin.
When putting a new trash or compactor bag in, make sure to allow four or five inches of the bag to overlap outside the top of the container. Take the silver colored retaining band, holding it open, and place it over the top of the trash bag and down on the bin. Push down until it rest on the plastic lip of the container. Flip the latch closed.
To replace the bin (it can be a little tricky) make sure the upper retaining ring is on and tight.
Place the hooks on the upper and lower retaining rings onto the mounting bracket on the inside of the door of the compactor. Once you are sure both hooks are in the slots, push straight down until the bottom of the bucket is resting on the metal stop at the bottom of the door bracket.
The compaction bin and trash bag are now secure and ready for operation.