Click on "Upgrade from Logic Express or Big Box" on the Apple Store's Logic Studio webpage. Purchase the current Logic Pro upgrade from the Apple Store.
Insert the upgrade disk into the optical drive on your Mac.
Double-click on the “Install Logic Studio” icon. The installer will start up and scan your system. Click “Next” to continue.
Click “Next” to continue past the “Welcome Information,” the “Before You Install” and the “Software Licensing Agreement” screens. Agree to the licensing terms when the pop-up dialog box appears.
Click on the desired install location, which is typically your default hard drive. Click “Continue.”
Enter your name and the Logic Studio serial number into the text fields. Include the dashes in the number, which is printed on the front of the user manual. Click "Continue."
Enter the serial number of your old version of Logic Express. This number is printed on the user manual. If you're upgrading from Logic Express 6, insert the USB XSKey that came with the old software rather than typing in a serial number. Click “Upgrade.”
Type in the user name and password for your Mac and click “OK” to start the upgrade to Logic Pro.
Insert the other installation disks as prompted. The installer will display a “Success” message when the installation has finished.