To change the password of any account you will need to be logged in with administrative rights on that PC.
Open Elevated command prompt.
To know all the accounts that has been created on the PC enter command net user and press enter. It will display a list of all the accounts.
Enter command net user <username> to see a list of all the set properties of the user. Example, net user Pratap, in this case.
To change password of any account enter command net user <user name> *. This will prompt for new password and confirmation password and will not display anything while typing. Example, net user Pratap *
Once it displays The command completed successfully, you are done. You can check it by logging in to that user account.