T-mobile Prepaid Cell Phones plans in Mexico?

   I was in California and now shifted to Mexico. There I was very happy with my T-Mobile prepaid cell phone and was using the same since last 3 years, but here in Mexico I am not aware about the services and plans. Is there any T-Mobile prepaid cell phone user who can guide me to solve all the queries such as services, network and plans?  Is it possible to have a new T Mobile prepaid connection for an unlocked cell phone without buying a locked cell phone at the time of new connection as I already have an unlocked cell phone and not in budget to buy a one more.