If you are using LumaShare and it already has photos from your last event or would like to clear the existing photos, you can do the following:
For dslrBooth /LumaBooth:
Go to Settings > select your event name, then click Go to Saved Events.
From there, choose your event and click Rename Event at the top.
Please keep in mind that LumaShare will only download images from the last 24 hours for your latest album.