Copying photos to external hard drive
Hi, I am trying export photos from my Macs photo library to an external Seagate hard drive but it's not simple! I've tried opening the picture library and dragging the photos library to the external drive but it won't allow me to do this. I've also tried exporting but I get the following message "could not write file to destination (1001)"
Can someone tell me in simple terms how to do this please?
Thanks!
MacBook Pro 13", macOS 10.12