Just a suggestion but if you make the sliding part removable with slats all the way up to the top you can remove the angled pieces in the bin because you'll be able to walk right in. Might have to widen it a bit, that's generally the best way IMO.
That bin is a thing of beauty! It looks just like the cage I keep my wife in at night. If she ever chews her way out, are you available to build a new one for me?