2003 S60 Rain Sensor Replacement

[thirdstick]

Hello, all.

When my car was purchased, it already had an aftermarket windshield installed..complete with rain-sensor that was never properly installed (or compatible with the glass?) Not sure why it didn't work, but it never sensed rain regardless of my sensitivity setting. Anyway, today, I noticed that the sensor unit was hanging off the windshield and that it doesn't look too good. [see picture]

The frame around it is completely broken and I even see a spec of broken glass from the previous windshield on it. Would anyone be willing to share detailed instructions on how to properly replace or fix this sensor and have it adhere to the windshield? Perhaps also instructions on how to remove it from another car at a salvage yard if its possible to find one in good condition second hand?

Thanks.