Writable NTFS on Yosemite
Remove osxfuse if installed via homebrew:
brew uninstall osxfuse
Install osxfuse binary and choose to install the MacFUSE compatibility layer
Reboot (optional but recommended by osxfuse)
Install ntfs-3g via homebrew:
brew update && brew install ntfs-3g
Link mount_ntfs:
sudo mv /sbin/mount_ntfs /sbin/mount_ntfs.original
sudo ln -s /usr/local/Cellar/ntfs-3g/2014.2.15/sbin/mount_ntfs /sbin/mount_ntfs
Reboot