Swap Line Up

You can swap any character that is minimum level 1 into your lineup. Go to "Line Up" on the side bar within the GNO City.

If you scroll down below your line up you will see all your Level 1 or higher Characters that you can swap into your Line Up. Choose which character you want to use by clicking it and then on the right hand side you will see this:

Once you have chosen your character you will need to choose which slot of your line up you want to swap out.