Mexico tourist change work visa

Generally speaking, since your friend is an employer, he should apply to the Immigration Bureau for a work visa for you. I'm afraid it's not enough to have a work certificate, as follows:

Original and photocopy of ID card, original and full-page photocopy of household registration book.

Original and photocopy of passport 1, 4 photos of passport size (2 inches),

China's birth certificate and notarized documents with no criminal record in China.

Specific information of the employer's company in Mexico, work contract, insurance, etc. You should apply to immigration. Note that it is a visa return.

Theoretically, a tourist can change to a work visa. As long as you submit your application, you will extend your residence qualification.