MSSQL have its own database management tool called as "MSSQL Server Management Studio (SSMS)". Here are steps to reset SA password using SSMS :
1] Open SSMS management console, it will prompt for authentication details,
Select Server Type : "Database Engine", Server name : IP / hostname of your MSSQL server Authentication : Windows Authentication
Once you select Authentication type as "Windows Authentication", the user name and password fields will be grayed out and it will allow you to login SQL server without entering login details. Windows Authentication is possible only when you are logged on same server in RDP on which SQL service is present.
2] once you are in, under "Object Explorer" expand Security and then Logins 3] locate and right click on user SA and select Properties 4] under General section enter desired password in front of "Password:" and "Confirm Password:" 5] hit OK at bottom.
This is the easiest and secure way to reset SA password instead of using any third party non secure tools