With File Roller you can edit an existing archive by adding new files, removing unwanted ones or by changing their names. You can work with folders in the same way as with files.
Add files to an existing archive by following the instructions on Create a new archive page.
Select the file.
Click Edit ▸ Delete, or right-click on the selected file, and choose Delete.
Select the file.
Click Edit ▸ Rename…, or right-click on the selected file, and choose Rename….
A dialog will open. Enter the new file name into the text entry field.
Confirm the name by clicking Rename.