Download and install the Nokia PC Suite on your PC.
Connect your device either USB cable or Bluetooth (either will suffice), and run the Nokia PC Suite, your device should be connected and displayed at the bottom (see picture).
Click on the "Install Applications" Icon.
You will be presented with the screen below once it loads.
- Now you need to find the theme or application you have to install using the left side of the screen.
- Once located, select it and click the "Arrow" in the middle to start the installation.
- From now on you need to pay attention to your handset's screen.
- Follow the prompts on your handset to install the application or theme.
If you have any problems with either Certificate Expired or Security Certificate Error please visit the respective thread. If you have an Unsigned application, you will need to Sign It yourself to install.