I missed the first few pictures of assembly.  Sorry, I'll try to get some on the next one and update here if possible.

Cut all pieces out.

Lay sides together and glue the puzzle piece connectors while they are flat.

Place glue on the end piece tabs and place into the bottom of the side section.

Start rolling the side tabs into the bottom piece.  Some of the fits are tight around the living hinge.  Be careful.

I used a good sized clamp to hold the pieces together while i got the  top ready.

Same process to get the top on. I used an Xacto knife to help fit the top on.