To update simple static content on your Samsung screen with a USB drive you will need to use the following instructions.

Step 1:

Turn off the screen, either with the remote or at the wall

Step 2: 

Unplug the USB drive

Step 3: 

Take the USB drive and update the content using a Windows PC, ensure the content is a jpeg image no larger than 1920x1080 pixels (or 1080x1920 for portrait screens). 

Ensure the content is named the same as it was before, usually 1.jpg

Step 4: 

Plug the USB drive back into the screen

Step 5: 

Turn the screen back on, the content should auto start.