Unfortunately there is no way to merge or rename recording yet. This is a feature we are working on. Same goes for editing and re-uploading replays.
However, if you download and edit one of your recordings, our support staff can upload it to your event from our side. To do so, please complete the edits on your replay and reach out to Support@Meetn.com with the details of which event to replace.
We know it's not the ideal situation right now, but we will have nice and easy to do for you in the future!