ka24de Upper intake manifold removal

[1slowlance]

What's going on guys? Name's Lance, fairly new to the scene. I've had this s13 hatch with ka24de for about a month now, and it's had a coolant leak somewhere since I've had it. Finally located what must be a pinhole in one of the coolant hoses under the intake manifold. So, I go about taking it off. I've got the harness unplugged and pulled out of the way, fuel rail is off, all nuts/studs holding manifold to block are off, and unbolted from the lower manifold. I removed the two studs holding the upper in place to the lower part of the manifold, and it moves freely. I see a hose connected underneath which looks like an air line, not really sure this is my first time really getting this far into a ka. Now, I've got everything loose, the mani moves freely, I just cannot get this last screw off/loose. Not really sure what it's going to, does anyone have any ideas as to what I could do? It seems like a square head might fit into it, I tried using the biggest phillips bit I have and no luck, plus there's hardly any room. Any suggestions/advice would be helpful. Thanks everybody.

http://i.imgur.com/kC8eUzm.jpg