This article applies to 123-reg VPS hosting running cPanel.
This article will explain how you can add your own theme to your 123-Reg hosted VPS using cPanel.
Login to cPanel WHM interface.
Click on the Themes link.
You can then click on the Universal Theme Manager link.
Then click on the cPanel Manage Themes link.
Upload your new theme using the Install Theme field.
Your new theme will now be added to cPanel.
Please note: To change your theme in the customer interface, use the Change Style link.