How to remove this?

[sy_imagine]

Hi everyone,
Because I don't know what is the name for it, please have a look on the picture I attached.
My question is, how can I remove this part? I would like to seal it, because when it rains water comes inside to the boat. I already unscrewed the screws also on the screen but I still can't move this part. I hope I don't have to remove the whole screen.
Thank you for any advices.

[tiger79]

The moulding runs under the screen, so I think you'll have to remove the screen first.  The moulding is likely to be glued down with sealant as well as screwed. 

An alternative might be to mask the edges of the moulding carefully and then apply white sealant to the groove.

[Yngmar]

The cover for the hatch garage? I've had that off. Good news is, you do not need to remove the windscreen to remove it. You undo the screws that hold the cover and the screws that go through the center-section of the windscreen into the cover. Then you can slide the cover out from under the windscreen. Can't remember if it was forward or aft, probably forward I think. Lift the front end upwards first (by the drain channels). It'll be obvious when you do it. If there is old sealant, you'll have to cut it with a putty knife first.

Bad news, I think you will find this isn't where water leaks into the boat from. The cover is just that, it doesn't seal any inside parts of the boat. The water can run in, and then back out through the two moulded drain channels on the front. The sliding hatch itself has the seals around it, you can see those from inside the boat. But perhaps you find a hole beneath that someone left for you!

[sy_imagine]

Good news: I was able to remove the cover (with a knife and hammer). Bad news: there are only screw holes for water to come through.
We live permanently on the boat. In the winter when it rained we had water dripping on the ceiling above the cockpit table and behind the stove above the ceiling. After we had properly covered the gap for the sliding door with foil, hardly any water got in. When it rained without foil and screws, a lot of water comes in.
Now when watering from the hose without a cover, no water penetrates. It is to despair.
I will seal the screw wholes with butyl and then wait for the next rain.