How to disassemble Hifi elite super 66 by Modern Portable?

The USB charging port of my 1-year-old hifi elite bluetooth headphone is broken, with the receptacle broke off after several attempts of wiggling the charging cable and cleaning the port . I want to open it up and put a new one on the PCB inside. Does anyone know how to do so? The customer service of Modern Portable says it rarely happens and they don’t know how to open it.

Thanks..