Hello,
As Jeff mentioned such a tool does not exist.
However, downgrading is easy to do manually since the extra files can just be ignored.
1) To downgrade an Admin to a Reseller, edit:
/usr/local/directadmin/data/admin/admin.list
and remove the Admin from the file.
2) Edit:
/usr/local/directadmin/data/admin/reseller.list
and add the account to the file.
3) Edit:
/usr/local/directadmin/data/useres/username/user.conf
change:
usertype=admin
to be:
usertype=reseller
and.. that's all there is to it for a downgrade.
John