To edit a variation and its options: 

1. Edit an existing product
2. Find the variation you want to edit in Variations section. Click Pencil Edit Icon
3. Update the Label, Required, or Display option. Click Options
4. Find the option you want to edit. Click Pencil Edit Icon
5. Update Price, Cost, Weight, Pre-Selected, and Images. Click Update
6. Repeat step #4 and #5 for additional options you want to edit
7. Be sure to Click Update from Variations section