Disambiguation note: this term is different from chingar and chingadera.
Chingarle (cheen-GAR-leh) means to work hard at something. It is used in expressions such as voy a chingarle un rato más (I'm going to work a little longer) or estuve chingándole a mi tesis del doctorado por cuatro años y todo para terminar escribiendo este pinche blog para gringos que quieren pasarse de lanza y mentar madres cuando vayan a ponerse hasta las nalgas en el DF (I worked my ass off for four years writing my PhD dissertation, all that to end up writing this stupid blog for Americans who want to swear and say insulting things when they get shit-faced in Mexico City).
Just for the record, it takes an average of 5.3 years to complete a PhD dissertation in the social sciences. However, it takes many years more to remove the memory of the silly Renaissance costume that PhD candidates are forced to wear in public in their graduation ceremony.