One of the biggest and best e-commerce shopping carts is Magento. Magento has a free version at Magento Commerce. This system can be quite confusing when you are trying to change your theme. It isn’t like most other systems where you get one folder and all you have to do is upload it and activate it. I have put together a walk through on how to install/change your Magento theme.
First off you have to go out and find a Magento theme. Some of these are quite expensive but come with much more than just your typical free one. The first place I would check for themes is ecommerce-themes they have quite a few really nice looking themes for you to download. After getting your theme, it should come in a zip file extract those on your computer. Inside the extracted folder you should get two folder called app and skin.
The next thing you have to do is add those folders to your Magento installation. This requires you to ftp into your site. The app and skin folders go in different places. The app folder needs to be uploaded to your magento/app/design/frontend/default directory and your skin folder needs to be uploaded in your magento/skin/frontend/default directory.
Magento CMS Manage Pages
Now that you have these folder in your Magento site we have to go through the admin to tell the site to use the new theme. First log in to your admin and go to the CMS tab and them manage pages.
Custom Design Pages
Inside there you will have to change every pages custom design to your new theme name you installed.
System Configure Design
Next you will have to go to the System tab and then Configure. Inside the Configuration section go under Design and change all of the relevant fields to your new theme name. Make sure you save everything and your theme should be up and ready to go.