These are all valid ways but not by far the simplest. For small files, once you are connected to your E2C remotely it's as simple as copy/paste or drag/drop from your pc to your remotely connected E2C to copy your files over. For larger files that may not copy this way you can easily add the volume your files exist on as an available local resource then you will simply copy the files from drive to drive on the E2C directly.
- After launching remote desktop before connecting - click 'show options'
- On the Local Resources tab under 'Local devices and resources' click 'More...'
- Put a check in the resource you want to be available and click 'OK'
- Connect as usual and your resource will now be available on the E2C to copy from.