First, get them to do a diskutil list and read back values. The get them to enter the disk number in. Test what they have put in against the size listed in diskutil, and if OK, then get them to enter the image name and it will automate the rest of script
Make a script based on https://computers.tutsplus.com/articles/how-to-clone-raspberry-pi-sd-cards-using-the-command-line-in-os-x--mac-59911
First, get them to do a
diskutil listand read back values. The get them to enter the disk number in. Test what they have put in against the size listed indiskutil, and if OK, then get them to enter the image name and it will automate the rest of script