If you wish to view the individual components of a Clause Set, click the <Expand> button that will appear between the two panels of the Clause Selection Screen when a clause set is highlighted.

Once 'Expand' has been clicked, the resulting list can be used and manipulated in the same fashion as if you had manually inserted the clauses individually. You can rearrange the clauses, remove any of them, and add to them from items listed in the left panel.