As you know, Lightroom is very user friendly and has some amazing features to use, like the Lightroom Smart Preview. This is what we will use to receive and send your images to you once fully edited.
If you are unfamiliar with this, please read more about it on the Adobe website and watch their YouTube video for more information.
If you still need some help we will email you the steps of what to do.
How to use Smart Preview
The other alternative will be to upload and download your images in DropBox