how to fix

 

Any specific area where it's leaking?

There have been cases where the glass has separated from the frame, allowing water to enter between the glass and the hatch frame. Or it could be a damaged weather strip, allowing water to enter between the roof panel or fender and the hatch frame.

 

separation of glass from metal frame at lower bottom back end of glass

 

I would imagine that you would need to hire a glass company to pull the glass and re-seal it.