PrestaShop Installation Instructions
First, download the last stable version of PrestaShop to your local computer. You can download it from the download section of the official site. Then unzip the downloaded archive. The unzipped archive should contain a folder called prestashop that holds the PrestaShop files and directories. Using an FTP client, upload them to your hosting account.
If you want the store to be accessible at the root URL address (yourdomain.com), upload the files and folders inside the prestashop folder to the root public_html directory on your account.
After that you have to create a database and add a user to it. You can do this from the Databases section of the Pixie control panel.
The next step is to open with your browser the URL address of your PrestaShop. This will start the automatic installer. On the first page you can choose the language that will be used during the installation (e.g. English, French, German, Italian, Spanish). On the same page mark the button for I want to install a new online shop with PrestaShop, mark the checkbox to accept the license agreement, and click on the Next button in the lower right corner of the page.
On the next page you have to provide all the necessary MySQL database information. Leave the server name to the default localhost and the database engine to InnoDB. Type in the respective fields the name of the database you created earlier, and also the username and password of the user for that database. On the same page you also have to choose the installation type. Full mode is the recommended type, especially if you haven't used PrestaShop. The last thing you have to do on this page is to type your email address, then click on the Next button to continue.
On the next page (Shop Configuration) there are some shop and merchant settings that you have to configure. They include the name of the shop, admin password, etc. After you're done click on the Next button to complete the installation.
There are also some additional security-related things you have to do after you complete the installation. You have to delete the install folder from the root PrestaShop directory on your account, and you also have to rename the admin directory. You can do both things either from the Files section of the Pixie control panel, or with an FTP client.
For some more details you can also check out the PrestaShop Installation Tutorial.