Many late model Nissans and Infinitis no longer use screws for the "oh s#%t" handles in the headliner, instead using handles held in with spring clips. These can be a genuine Chinese puzzle if you don't know how they work. To remove them you'll need three tools, a small hook, a small slot screwdriver or prybar, and a needlenose pliers (preferably with a good, sharp nose).
This is what you'll see when you pull the handle down. The little tab at the top center is the pawl that releases the plastic retainer from the body of the hinge:
To remove the retainers, use the hook tool to pull the tab towards you (red) while simultaneously prying upward at the seam between the retainer and the hinge body (green). The whole retainer will slide upward and out:
Once loose, you'll see the spring that holds the whole thing together:
After removing both retainers, the handle will slide off the springs:
The springs are held into the rectangular holes in the sheet metal by a pair of pawls top and bottom. Butt the nose of the pliers up to the sheet metal and grab these pawls, not the big metal tongues. Grabbing the tongues will probably allow the spring to fall back through the hole and behind the headliner, making your life very complicated! The second pic shows a spring grabbed properly with the plier tips:
Once the springs are removed, reassemble the entire handle, springs and retainers. This is how they come at the factory, as an assembly that the workers simply snap into place. First, reinstall the springs, making sure the little oval locator is through the oval hole in the back of the spring:
Then reinstall the retainers by pushing them down (red) through both rectangular holes in the spring (green) until they snap into place:
The assembly should look like this, and will simply snap back into the holes when the rest of your job is finished:
Hope this helps you, and happy motoring!