Foreigners who, for one reason or another, have to extend their stay in China or have their visa changed into another category should go to the local entry and exit administration in time to file an application;
The following are the formalities one must go through when doing so:
(1) Present the passport, visa and other documents;
(2) Fill in the application form for an extension or change of category;
(3) Supply proof for the necessity of such extension or change of category;
(4) Pay the fee(s) for the issuance of visa or documents