Clean the cans and remove the labels.
Paint the bottom and sides with white paint
Use a hammer and nail to make a hole in the center of the bottom of each can, large enough to thread your twine.
Separate your napkins into 1 ply.
Carefully glue the napkins onto the cans with mod podge or watered down white glue. Leave a little overhang on the top and bottom.
Coat the top of the napkins with more mod podge or glue.
Use a nail file or sandpaper to file off the extra napkin on the edges.
Spray each can with a couple of coats of polyurethane to protect them
Thread a long piece of twine through the largest can from the bottom.
Leave enough twine to hang the windchime from and then tie a knot underneath to hold the can in place.
Thread the next largest can under the first can.
See where you want it to hang and place a small piece of tape there. Then pull the thread back out to tie a knot where the tape is.
Thread the last can and this time you'll just have to work with the twine to make a third knot to hold it at the spot you like.
Trim off the excess twine under the 3rd can.
Tie a loop at the top and hang it where you like.