If you try to go out the breech end you have to get everything past the trigger sear and auto-safety tab, and think of all those spring coils getting hung up on the sear. I found it to be easier to set the power wheel low, like #1, to reduce preload to the spring, remove the barrel screws, unscrew the little allen screw on the power wheel (don't drop it, it's small!), and then slide the guts out the barrel end. With a little "practice" you can do it in under a minute.