How can I apply another 2 months visa or to extend my visa?

If you hold tourist L type, you may need to provide your passport, the completed application form, a recently-taken bareheaded color photo, registration form of temporary residence, accommodation arrangement and the return ticket as well as other requirements. Then, apply for an extension 7 days earlier before it expires at the local PSB within mainland China.
There is no specific requirement for how many times you can apply for the extension. So maybe you can do that for two or three times.