Transfer users from LDAP to basic auth

We have accounts created from LDAP. We want to disable our LDAP and manage those accounts via Grafana api. We disabled LDAP auth in Grafana, wrote an api that set user password same as it was in LDAP and tried to log in, but it didn’t work. If I understand correctly, user can’t login via password if he’s got authLabels: [“LDAP”]. Is there any way to drop that field? We currently use Grafana v6.5.3