1. Log onto your Teamspeak 3 server.
This is done through the Teamspeak 3 client.
2. Right-click your server name.
Once you have logged onto your TS3 server, right click the name of your server (above any channels, subchannels and logged-in users you may see.)
3. Select 'Edit Virtual Server'.
After right-clicking the name of your server, there will be a menu with several options to choose from. Select Edit Virtual Server.
4. Choose your new password.
That will bring you to the area where you can change your password. In the Password field, enter the server password you would like the server to have, then click OK at the bottom of the menu.
5. Confirm the new password.
You will be prompted to confirm the new password you'd like to set. Retype the password, then click OK.
If you mistype the password in this step, you'll get an error message and be redirected back to the server screen. If that happens, head back to Step 2. Otherwise...
6. You're done!
The password has been set and you're done. :)