Right-click on the Composite Face name in the Feature Tree, in the popup menu that appears, select Edit Feature.
The Feature Guide will appear automatically open to Required Step 2. You now return to the same situation in which you created the Composite Face.
Make modifications in the current step, and / or click the icon for
Required Step 1 to modify that
step. Press OK 
or
Apply 
in the Feature
Guide to complete the function.
Note: If your changes result in a geometric impossibility, or cause problems in subsequent functions, you will be warned by the Conflict Solver.
See also: