You can't. Tianjin Happy Valley official website query shows that Tianjin Happy Valley tickets are regarded as consumption after being verified in electronic certificate, and cannot be returned, modified or transferred. Unused e-Certs can apply for full refund within 30 days after expiration, and cannot be returned after expiration. Tianjin Happy Valley is located in Dongli Lake Resort in Tianjin. There are 34 attractions in the park, which is an excellent choice for parents, couples and friends.