How to change student visa to business M type/work Z type

Hello
I am a masters student in china since 2014 and now i want to change my student X type to business M type as i am starting a trade business here.
I have already applied for the trade license showing my office space and the processing is going on.
Now How can i change my student X type into business M type without traveling back to bangladesh? whats the procedure and what documets are required?