There's no set limit to how big or small your piggy bank should be, but you should aim for a plastic bottle that's between 500–1,000 millilitres (17–34  fl oz). Wash it out with water and let it sit for 10 minutes so it can dry. Keep the bottle cap on the bottle. It will serve as the pig’s snout. Cut out 4 egg-holders from the carton using scissors. Then, have an adult use a low-heat hot glue gun to attach them to the bottle by applying the glue around the edges of the egg-holders. Finally, paste the legs on the side opposite the coin slot. When the pig is standing on its new legs, the coin slot should be facing up. Now that you’ve got a basic pig shape, it’s time to get artistic with your creation! Make a tail by twisting a pink pipe cleaner into a spiral. Draw nostrils onto the pig’s snout with a black marker. Cut 2 triangles out of pink paper or felt and glue them on as ears. You can give the pig eyes by hot gluing googly eyes onto its face, or by drawing, cutting out, and gluing on eyes yourself.

TL;DR in Vietnamese:
Rửa sạch chai nhựa bằng nước máy thông thường. Gắn chân vào thân chai ở phía đối diện với khe nhét tiền. Trang trí cho con lợn bằng các vật liệu còn lại.