Assembly structure is different from part structure and most of the time it is meaningless to think of rerouting assembly components. In bottom up design you need to change assembly constaint references for a successful rerouting.
In top down design you need to change the relations or skeleton structure.
You can, but not thought the 'Quickfix' route. You need to 'fix model' > 'component' > reroute. However you can only rerout the assembly referecnes and not the component references. To do this you need to redefine the component placement.