How to run Unreal Engine from external drive? (Mac)

Hello everyone.
I recently downloaded Unreal Engine 4.10.2 and to save room on my computer I moved it to an external hard drive. I found the folders of files and moved them all over so I believe I am not missing anything but when I open EpicGames Launcher on another computer it says that I need to download it to that computer. This completely defeats the purpose of having it on the external drive.
I looked around the forums and saw a few similar questions but none have answers.
Thanks.

Hello,

Thank you for reaching out to the Epic support team. We have recently restructured our support system to better assist our users across Epic’s growing catalog of products.

Epic Games launcher support will now be handled by our Player Support team through an email ticketing system and active knowledge base. This support will encompass the download and installation of the launcher and the various Epic Games products hosted on the launcher (UE, UT, Shadow Complex, Fortnite, and Paragon). The launcher support team will also handle connection issues related to these products. The launcher support site can be accessed here (http://help.epicgames.com/).

Traditionally, Unreal Engine support has been handled through AnswerHub, and this particular process will not change. Users of the Unreal Engine may continue to post questions and issues as normal and interact with the engine support team. Any questions or issues that arise prior to the successful installation of the Unreal Engine should be directed at the website above and the launcher support team.

Those seeking assistance with the other individual products may do so through the following pages:

Unreal Tournament - http://help.unrealtournament.com/

Shadow Complex - http://shadowcomplexhelp.epicgames.com/

Fortnite - Coming soon

Paragon - http://paragonhelp.epicgames.com/