cut the jeans leg to 2 inches longer than the water bladder
cut the reflector to the same size as the bladder
Step 3: Sew bottom
now you have to sew the bottom of the jeans so that the bladder doesnt fall out. you have to turn the jean inside out, then sew the cut side shut about 1 inch from the end. turn it back the right way and push it so it looks right.
Step 4: Insulation
in this step you will need to put the insulation inside the jean so it looks like a liner. push the insulation to the edges so its tight agianst the sides. mark the spot where the insulation edges meet. pull it out, and sew the insulation together it should look like the photo.
Step 5: Insulation continued
now put the liner inside the jean "sock". it should fit snugly inside the sock, with no edges protruding. squash it flat, and then stitch one corner of the sock to the liner. whe this is done, stitch the diagonally opposite corner together. this should be enough to stop it falling out.
Step 6: Finished
all you have to do now is put the bladder inside it, and use it.