I have a MacPro1,1 running Mavericks 10.9.5 that I set up with SFOTT. Today I noticed that there is a security update from Apple and that it includes an EFI patch. If I install this update, is it going to break my system? I'm going to have to load this update - as my work will require it, but I also don't want to break my system. Is there a certain procedure I need to follow?