It sounds like you want to use Target Disk Mode, which is not possible without a FireWire port.
However, if you have a network, just connect both computers to your network. Then on the MacBookPro, enable Sharing (System Preferences > Sharing) and then on your Mac Pro connect to your MacBookPro from either Go > Connect to Server or via the Finder (Sidebar, look under Devices for the name of your MacBook Pro). Note: or, you could do the reverse, sharing your MacPro and connecting to it from your MacBookPro.
If you don't have a network, you should just be able to connect an ethernet cable between the two computers and follow the sharing procedure I mentioned above.