<ul>
<li>Start from L3
<li>turn down 180 degrees the two south tiles on top of the two stacks
    and arrange the two superposed tiles originally in the north-most position such
    that in the end we have a 2x2 square such that
    in the north row we have a stack of 2 tiles (left) and 1 tile (right),
    whereas in the south row we have a stack of 4 tiles (left) and 1 tile (right)
<li>Now open in 3D with the following hinging:
 <ul>
 <li> the two stacked tiles in the north-left position are hinged along the north edge
 <li> the upper two stacked tiles in the south-left position are hinged along the left edge
 <li> the two middle stacked tiles (SL) hinged right
 <li> the two lower stacked tiles (SL) hinged south
 </ul>
<li>End up with the final shape
</ul>