P0751 Shift Solenoid A Perf Code

I have a 2000 Pontiac SSEi and my check engine light came on. The code is P0751 Shift Solenoid A Performance Stuck Off. Where can I find this solenoid on the car to replace it? Can anyone tell me how to do it? A few pictures would help if it is hard to locate. Would like to avoid an expensive car repair bill. Bad time to have to repair a car. Hopefully I can fix it myself. Has anyone done this before?
Thanks,
Bob