1. First, cut off the bottoms of the bottles approximate, afterwards cut off the excess material, along the burr with the small scissor.
2. Cut out the auxiliary construction and stick it to the edge of the cut-out bottom with adhesive tape.
3. Use the thick needle to pierce the bottom, where the auxiliary construction marks the stitching-holes with dots. For holding the needle us a combination pliers.
4. Remove auxiliary construction
5. Before sewing. Open the zipper. Start to stich with the small needle. 3 cm. after the zipp-start and sew the zipper all around the first bottom
6. Attention! Don’t complete sewing the whole circumference, before finishing, overlap the zipp-fabric end, that’s how you build a nice PET.