Step 10 - Door with lock
Now you can fixate the edge protection with a stapler to the hole where the segments go through like in the picture below.
To better lock the door in place I drilled a little hole from the sides and from above through the side panels right into the door. So you can insert a nail as lock machism #1, as you can see from this picture.
Finally you place the actual lock into the doors bottom edge for example. Be sure to apply a piece of wood to the casing where the lock can lock into place. I sure bet you can figure this without a picture :D
Let there be light!