Hi! =)
Just got my Phaser 7760GX installed okay with Yosemite, using just a simple trick.
There's a plist file in OSX which states the version of OSX - in this case - mine was 10.10.1
I changed this to 10.9.5 - which is Mavericks, and the driver then installs fine.
Once the driver is installed, you can put your OSX version number back to 10.10.1 or whatever it was in the first place, and your Xerox Phaser driver will still work, =).
The only reason the current driver installer doesn't work, is because it's not expecting the OS version number to be higher than OSX 10.9.x.
The file with the version number to change, is SystemVersion.plist and it is found in your hard drive, in the system folder, in the library folder, inside of the CoreServices folder (Harddrive->System->Library->CoreServices). You won't have permission to change the file at first, but you can either change permissions on the file to allow it to be edited (right click the file and choose GET INFO, then edit the Sharing & Permissions settings for the file), or simply make a copy of the file on your desktop, edit that version, and then copy it back to the CoreServices folder. Also, it's good practice to make a copy of the original file before you make any changes, just as a backup, =).
There are two other applications that require this trick to work in Yosemite - Media 100 a video editing app, and Matlab (I've no idea what that app is - lol) - and there are video tutorials online to show you how to change SystemVersion.plist for installing either of those. Well, it's exactly the same for installing the Phaser 7760 Xerox drivers! =).
Here's a link to the general SystemVersion.plist trick:
http://www.macbreaker.com/2012/01/how-to-spoof-your-version-of-mac-os-x.html
Here's a link to how I used it to install Media100 (probably the clearest steps):
https://www.facebook.com/video.php?v=10152394100812015
Here's a link to how someone else used the trick to install Matlab:
https://www.youtube.com/watch?v=GoQnzIyOkB0
The great thing about the Xerox Phaser 7760 drivers, is they work under Yosemite just fine! =). It's the install process that doesn't work. >_<. So once you've edited SystemVersion.plist in order to install the drivers, and then put it back to how it was afterwards, you'll never need to fiddle with it again! =D. Once the Xerox drivers are installed, you'll be able to print to the 7760 whatever your OSX version number, ^_^.
