Flash CS3 Tutorial
How to Edit Symbols in Flash
Open a document with a symbol on the stage.
Using the Selection tool (v key), double-click the symbol. You can now edit the symbol. Click the Scene 1 icon to return to the main stage.
A second way to edit a symbol is to select the symbol and choose Edit > Edit in Place (Edit Symbols or Edit Selected).
Returning to the main stage, open the Library (Window > Library (Cmd/L (PC-Ctrl/L )).
Double-click the symbol icon in the Library to edit the symbol using method three.