Install your FireStudio Pro's software on your computer, if you haven't done so already. Use the installation disk that was packaged with your FireStudio module, or download a copy of the software from Presonus' support site. Your computer will reboot after the software installs.
Connect your FireStudio to your computer via FireWire cable after your computer reboots. Attach the FireStudio's power cable to the power port on the back of the unit, and then plug the cable into a power outlet.
Connect your PD to your FireStudio, using a 1/4-inch to 1/4-inch stereo audio cable. Plug one end of the cable into the audio output on the side of the PD, and then plug opposite end of the cable into one of the audio inputs on the front of your FireStudio Pro.
Launch the FireStudio software. Click on the "Create a New Song" option at the application's welcome page. Type your project's name into the "Song Title" field, click on the "Empty Song" option and then click on the "Create" button.
Click on the application's "File" heading. Highlight the "Options" heading that appears in the "File" menu, and then click on the "Audio Setup" option. Click on the "Song Setup" button. The FireStudio's inputs will be diagrammed in the Song Setup menu.
Locate the input you're using for your PD, under the Song Setup menu's "Input" tab. Click on the input and then click on the "Add Stereo" button. Enable any other input you intend to use for your project. Exit the menu to complete your FireStudio's configuration for your PD.