I filed taxes in the wrong state how can I correct this?

I just found out I've been filing taxes in the wrong state. I'm military and I've move a few times which has caused me some confusion. I thought I was supposed to file taxes based on the state I was in. Recently I found documentation stating my state of residency is South Carolina. How do I correct the returns I've submitted in the past to make them reflect SC? How can I fix this?