Step 1:

Open Opera, select the menu button then click Settings

 
Step 2:

Click Browser and then click on "Change Proxy Settings" under Network.

 
Step 3:

Now select "LAN Settings"

 
Step 4:

Set your settings to match the image below, our HTTP proxies can be found here

Step 5:

Click OK and then OK again - now browse to any website, it will prompt to enter your TorGuard Proxy username and password - if your not sure of those, they can be managed here

Step 6:

Browse to TorGuard Whats My IP and confirm your IP has now changed.