Line up the base and lid sections so the short and long strips overlap as shown:
Drop the lid onto the base and start fighting to get the 3mm bolts into the blind nuts before it falls apart. It'll need a bit of wriggling but you should feel them drop into place. Tighten each a couple of turns to prevent it falling out then check nothing has dropped out of place. If it's OK, tighten the bolts up but not too much or it will distort the lid.
The stack of strips should look like this:
