I have recently had a Computer Crash and have set up a new Computer. However, I cannot find a way to synchronize my old Bookmarks. Part of the Problem probably is that when the Syncing was originally set up, I was using a different User Name [e-Mail Address] to that I am using now. I have been using Firefox since 2006; and have an old Sync Key dating from some time in 2014; but cannot find a way to enter it into the current Firefox Settings. How do I recover my Bookmarks?