I don't have a video, but hopefully this will help!
- Unzip Renedit into the GameName/game directory.
- Open renedit.rpy in Atom, Notepad, or any other text editing software.
- Locate the lines beginning with "init python" and ending with "config.keymap...". . (These lines only have one # instead of three!)
- Delete the # before these lines and save the file.
Then, just press "e" on your keyboard in-game to bring up the overlay.
Thanks! Maybe I'll make a download version specifically for drag-and-drop use for these cases.