Change all users with a role of “subscriber” to “pmpro_role_2”
for USER_ID in $(wp user list --role=subscriber --field=ID); do wp user update $USER_ID --role=pmpro_role_2; doneList number of users for each role
wp eval 'print_r( count_users() );' 
Bill Erickson is a freelance WordPress developer and a contributing developer to the Genesis framework. For the past 14 years he has worked with attorneys, publishers, corporations, and non-profits, building custom websites tailored to their needs and goals.