I need to set up Ubuntu Server on my VPS but CentOS 6 x86 is already installed there. How could I replace CentOS with Ubuntu?
I need to create 2 users. The IP addresses are 126.96.36.199 and 188.8.131.52. How will could I set up them with Putty?
You're asking multiple questions, each of which should be their own separate questions, but I'll answer them both here, anyways.
(1) (BACKUP ANY DATA YOU WANT TO KEEP BEFORE DOING THIS!) To change the Operating System, the VPS provider should be able to do that. If there's not an automated "Reinstall Operating System" option in the VPS control panel pages for your provider, file a support ticket with your VPS provider. If they tell you that you cannot switch operating systems, or that they do not have Ubuntu VPSes, then you won't be able to switch to Ubuntu (but most VPS providers have Ubuntu images)
(2) Once the VPS is set up with whatever OS, you should SSH in by specifying the IP address for your server, then it'll connect and prompt you for the username and password. Provide those, and once you're logged in, do
Your not going to be able to install Ubuntu without having KVM like access to the server and some help from the ISP. Usually you can select what OS you would want on your VPN at the time of order and in most cases change it at any time ( Losing any data on your server )
In answer to your second question open putty and make sure SSH is selected. In the text box that says Host Name or IP address put your ip eg.
then use the