switching X2 one-entry to X2 multi-entries

Hi, I will study in Guangzhou next semester and I'm therefore applying for a X2 (one-entry). However, I am planning to travel among the sorrounding countries during the semester. In this sense, I am wondering if it is possible to change my X2 with one-entry into a X2 with multiples-entries once in China. Is it possible to do it there or should I apply for a X2 with multiple-entries directly in my home country?
Thank you