Along with the print-out you'll need a straight edge and blunt knife for scoring, scissors or x-acto-type knife for cutting, PVA white glue and toothpicks for gluing.
Score on all the lines, straight and diagonal, that separate the four triangular faces of each tetrahedron. There are no guidelines for the diagonal folds. Align using the edge of the picture. Don't forget to score these!
Don't forget to score the tabs and hinges.
Cut out the pieces.
An x-acto type knife and straight edge works well, too.
Fold on all scored lines, keeping the photos on the outside and folding the unprinted sides together. (All mountain folds.)
Attach the two pieces by gluing tab 1 to the short, straight edge on the other piece.
Form the first tetrahedron. Glue tab 2 over tab 1, straight along the hinge. Glue tab 3 to the opposite edge and glue tab 4 along the 11 | 4 hinge.
Form the next tetrahedron by glueing tabs 5, 6, & 7.
Check that the hinge flexes.
Form the next two tetrahedra by glueing tabs 8, 9, 10 and tabs 11, 12, 13 in place.
Leave tab 17 exposed when you glue tabs 14, 15, 16 to form the fifth tetrahedron.
Five tetrahedra down, one more to go.
Fold the five tetrahedra into an equilateral triangle displaying on of your four photos. Create the ring of tetrahedra by glueing tab 17 to the short, straight edge.
Form the final tetrahedron with tabs 18, 19, 20.