The VBA editor can be opened at any time by pressing the ALT+F11 keyboard shortcut. From here, you can access the code for all open workbooks.
You can double-click any workbook, sheet, or module object in the Project window to show the VBA code contained in it. Recorded macros will always appear in modules, which is where you’ll typically want to write your own macros too.
For more information about editing macros, see the article “Editing Excel VBA Macros“.