Once you purchased uDropship (and pro), you should be provided with a download link for the software. When you click on it, it should download a zipfile to your local machine.

• Unzip the files
• Place them in the appropriate directory in your magento installation.
• Place the license file in the /app directory
• Clear your cache in your magento installation
• On the Magento Cache page, hit the green button labeled “Flush Cache Storage”
• If you are logged into the magento Admin, Log out and re-login.
• You should now see a new menu item, Dropship under the Sales Tab and Drop Shipping under System→Configuration, under the Sales section.