You can either put them in manually or get it done on auto. There's also a REMOVE ALL option at the end of the list of your garmanet grids. If you want to equip it, go to equip, other wise if you only want to change the sphere, go to Garment Grids, pick a grid, click on it, and your spheres should come up and use your little arrows to pick a node if it doesn't do it automatically. You can always as SHINRA on deck for the tutorial.