To remove permanently ACL from a file:
# setfacl -bn file.txt
To remove permanently ACL from an entire directory:
# setfacl -b --remove-all directory.name
To overwrite permissions, setting them to rw for files and rwx for dirs
$ find . ( -type f -exec setfacl -m g:mygroup:rw '{}' ';' )
-o ( -type d -exec setfacl -m g:mygroup:rwx '{}' ';' )
To set mygroup ACL permissions based on existing group permissions
$ find . ( -perm -g+x -exec setfacl -m g:mygroup:rw '{}' ';' )
-o ( -exec setfacl -m g:mygroup:rwx '{}' ';' )
You’ll probably want to check that the group mask provides effective permissions. If not you can do it the old school way and run this too:
$ find . -type d -exec chmod g+rwX '{}' ';'
.