This is a very short flow to follow. First you need to install “Macfuse”. You can get this small application from this link: http://code.google.com/p/macfuse/ . This application allows you to extend Mac OS X’s native file handling capabilities via 3rd-party file systems. It is used as a software building block by dozens of products. Then, one last step left. Now you can start with installing Fuse-ext2. This is an extension to macfuse, so the macfuse is required to install beforehand. Fuse-ext2 is a multi OS FUSE module to mount ext2 and ext3 file system devices and/or images with read write support.
If you installed these applications successfully, now you should be able to read/write ntfs and fat formatted disks through your mac