1537 Printing Press in Mexico City

While researching events pertaining to the arts in 16th century Mexico City, I came across two items on printing. According to Diana Fane's book Converging Cultures: Art and Identity in Spanish America (Harry N. Abrams, 1996), the printing press was introduced in Mexico City in 1535. Martin S. Soria, author of the journal article "Notes on Early Murals in Mexico" in Studies in the Renaissance, Vol. 6. (1959) claims that Giovanni Paolo (Juan Pablos) of Brescia, Italy, was the first printer active in Mexico (a. 1539-61). What was done with the printing press between its introduction in 1535 and Paolo's arrival in 1539? Was it used? If so, who was at the helm? Was Paolo just the first European printer active in Mexico?