How to Change InterServer VPS Root Password?
You can reset your root password on your OpenVZ server through https://my.interserver.net. To begin, log into https://my.interserver.net with your login and password. Select the VPS using the top right drop down menu or VPS-> list vps. This brings you to the VPS information page.
Click the arrow next to system management to open that interface.
Select “Change Root Password”
Enter your new root password twice.
Once submitted the root password will be reset with in two minutes.