Provider or reseller may change owner of a PBA-S hosting subscription usual way:
Top > Account Director > Subscription Manager > Subscriptions > %subscription% > Change Account
But owner of a registered elsewhere domain assigned to the subscription is not changed in PBA-S version before 4.5:
Top > Service Director > Domain Manager > Domains
Owner of registered elsewhere domain is changed together with hosting subscription in PBA-S since version 4.5. Here is request ID:
PBAS-26908 - The owner of the domain registered elsewhere, is not changed, when the subscription's owner is changed
Upgrade PBA-S to version 4.5 or higher once it's released.
Hotfix for PBA-S version before 4.5
Since the issue requires complex manipulations with the database, it is recommended to contact Parallels Technical Support for assistance.