Mark- the above is the link for removing the presets, could you be specific in the "motions" you went through? that way the community here can be more specific in answering your questions.
I don't see anything about removing External Editor Presets. I just want to remove them from the menu. Give me a list and a "Remove" button — that's all I ask. I've tried Clear, Restore Defaults, Save, and none of them do anything. The menu is permanent and unchanging, like conservative rage.
Go to Preferences > External Editor tab.
Select the preset from the pop-up - then click the pop-up again and you'll delete Delete X preset at the bottom.
Repeat for any other presets.
If that's not working, we'll need a bit more info. One alternative would be to go to the Preferences > Presets tab, press Show Presets Folder and you should find the External Editor preset files in there - you can just delete them using Explorer/Finder and restart LR.