Cannot manually remove Nextcloud database

Hi. After failing to completely install NextCloud (on a member server) I decided to uninstall. The manual scripts for removal worked for the most part until it came to the database. I have not been able to gain direct access using any user: Administrator, root, nextcloud, nc-admin or postgres thus cannot alter the PostgreSQL db in any way.
I would like to completely remove and reinstall the PostgreSQL db. I would like to avoid removing and reinstalling the UCS member server if possible and gain a bit of insight to administering the psql db in the UCS environment. Only the script regarding NextCloud failed and this server has been successfully domain-joined since initial setup.

All help appreciated.

UCS: 4.4-6 errata776
Installed: kde=5.8 kvm=2.8

please do NOT remove PSQL. It conains more than Nextcloud database.

This page explains something about backup and restore of Nextcloud and how to delete the Nextcloud database:

If you will need the PostGreSQL -password (by default not needed), you will find the password in *.secret - files in /etc/

Have success

Hello and thanks for your reply.
The link you sent doesn’t want to come up. Can you confirm that it is:

Unfortunatelly the website seems to be down or disabled ond only is available in German now.

Maybe this might help as well: