Though there are things you can correct on FAFSA, I do not know if this is one of them. If it is not, you do have to contact each college as @thumper1 says above.
One would think the FAFSA would allow this correction to be made, given it is an easy mistake to make. I seem to remember discussion on this some time ago. No idea if this year’s form can be corrected by filer—check it out because if it is correctable by you, it would be a heck of a lot easier than sending the info to each college, especially if you are applying to a lot of schools. But you do as you have to do. It’s a huge difference in EFC.