A post to their own boards. Let's see if I can find it for you.
https://forums.unrealengine.com/community/general-discussion/105868-how-do-i-completely-uninstall-epic-games-launcher
They have support links but a few other folders later that you get to clean up.
Please don't take this as the solution but my advice to go to their support boards.
Well I've really done it this time, I was having trouble with Epic Games and decided to uninstall then reinstall the launcher. BUT, instead of uninstalling, i deleted the folders the launcher was in. Then I tried to reinstall it, but, obviously, that didn't work, so I used CCleaner and Wise program uninstaller to attempt to get rid of all the remnants of the launcher, but I still can't reinstall it. I'm using Windows 10 if that might help. If anyone could help me out, I'd really appreciate it.

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