How to Enter a New Final Cut Pro Serial Number
for OS X 10.6.8 Snow Leopard Systems -
click on your MAC internal hard drive, and navigate to -
/library/application support/ProApps
find the file called -
Final Cut Studio System ID file, and delete it.
when you open up Final Cut Pro again, it will ask you for a new (legal) serial number.
For OS X 10.8.2 Mountain Lion Systems -
click on your Mac internal hard drive, and navigate to -
library/application support/ProApps
delete ProAppsSystemID
delete FinalCutStudioSystemID
navigate to -
library/preferences
delete com.apple.RegFinalCutStudio.plist
restart your computer. Launch FCP, and enter the new serial #.