How to make someone else a host on already recorded meeting, so they can edit it?

Yes, Moe can be added to a Meeting after a session. In Adobe Connect, the meetings are persistant, meaning that they remain until they are speicifically deleted by a user. They can be used over and over and can multiple sessions and recordings. Being assigned Host rights to the room, should give you the ability to to edit the recordings associated with that room. If that isn't working you may also need to add Moe to the Meeting Host group, as an administrator. It's been a while since I tested if that was also a requirement for recording editing. 

Larry just needs to add Moe to the Participant list for the room and assign the Host role to Moe. 

You just add the user to list on the right. Then select that user and use the Set User Role button to give them Host rights. they can then edit recordings associated with that room. 

Alternatively, you can move the recordings to the Content Library and give Moe Manage rights to the recording, and it will achieve the same thing. In either case, the other trick is Moe being able to get to the location where the recording resides to be able to have the option to select the Edit function for the recording.