Talk to casting as suggested above as they would have all the info you need, but also talk to your managers, they can usually help with that too. You can stay in your area if your area has a full time position open or you can be waitlisted for one to open in your area. Now granted it was way back in the day of the Dinosaur, but when I went from Part time to Full time, all I did was tell my manager and they sent me to HR right there at my location. I signed a piece of paper and HR sent it to casting with the open rec for a full time postion. It took about a week or two to process but I didn't "do" anything, between the manager and HR it was all done for me!
Talk to the managers of your area and they will direct you. It is a simple process, but again if there is not a full time position open in your area and you don't want to transfer you will have to be patient.