If you login to Medit Link this article will show you how to easily download your scans and attach them to the EasyRx case. During this process you will want to select Medit, STL and then leave the other options including the .jpg options blank.

Now the scans should save to your Downloads and then when you go to the Rx and can either drag those files into the Uploads box in the Rx, and then if you open the folder it will let you drag both scan arches. The STL files should upload to the Rx to be edited like if they were to have attached through the Medit integration.