Bulk editing is possible if your are familiar with HTML and CSS.

Steps

1. On the dashboard click the more button on the Maze you want to bulk edit.
2. Click Export Maze.
3. Unzip the file and open the *.json file in a HTML editor or text editor.
4. Use find and replace to make the changes in bulk.
5. Once you're done re-zip the file and import it back into your account.