I have tried so many things and searched so much that I am on the brink of insanity. Maybe someone can validate if this works for them:

Based on my test, I do not think that you need to transfer the file from the PC as indicated at the link above.

Simply upload to Txtr.com and download using the Txtr app. The file opens on the LCD screen using the app.

To view the file on the reader screen, browse to the /sdcard/txtr/ folder and add the Epub file to the library. I am not too happy about the uploading step, but only one copy of the file is downloaded to the device. The only negative is that Txtr.com seems a bit slow and it is not very intuitive.