CAB files – they’re a bit confusing for most people. If you’re told “Here’s a CAB file, go install it”, most users will be a little lost. Sure, you could follow our instructions however you can now use CabviaActiveSync. This free edition, courtesy of MoDaCo, lets you install the CAB file quickly and easily. Just download the CAB file to your PC, ActiveSync your device and then right-click on the file. An option called “CABviaActiveSync” will show – just hit that and you’re all done.
Link – CabviaActiveSync
EDIT – This needs .NET Compact Framework to run.