A reinstall wipes the disk and installs a fresh OS. You do it yourself from the service page, no ticket needed.
- Services → click the server → Reinstall in the VPS control card.
- Choose the operating system from the list.
- Set a new root password, or press Generate and copy it somewhere safe.
- Tick I understand all data will be permanently erased and press Reinstall now.
The task runs for a few minutes; the status is shown in Tasks. When it finishes, connect over SSH with the new password. Your IP addresses do not change.
Warning: everything on the server is deleted, including backups stored on the same disk. Copy anything you need first.