1. Verify All Other Fasteners:
* Screws: Double-check *everywhere*. Some screws are hidden behind the armrest, under the door pull cup (the little indentation in the armrest), or even behind the speaker grille. They might be small and easily missed.
* Clips: Feel carefully around the perimeter of the panel. These clips can be brittle and break, so gentle prying is necessary. Sometimes a small flathead screwdriver carefully inserted between the panel and the door frame will release them.
* Wiring Connectors: Disconnect any electrical connectors for the power window, door lock, or courtesy light. These are usually located behind the panel, sometimes near the armrest.
2. Investigating the Door Handle Mechanism:
This is the most likely culprit. The panel might be *slightly* hooked onto a part of the handle assembly.
* Handle Release: Some handle assemblies have a small retaining clip or tab *inside* the handle that must be released. You may need to explore the handle mechanism itself from the inside of the door to find this. This usually involves carefully pulling off the handle bezel (the outer decorative piece) and possibly removing the inner handle components. Consult a repair manual or search for diagrams online specific to your *exact* 1991 Nissan pickup model (e.g., D21 King Cab, Hardbody, etc., as the models varied).
* Careful Prying: Once you've ruled out hidden fasteners, *very gently* pry along the edges of the panel, starting at the bottom. Use plastic trim tools to avoid scratching the door. Work your way around the perimeter, feeling for any resistance – that resistance is the likely point of attachment.
3. Using a Repair Manual:
This is your best bet. A repair manual specific to your 1991 Nissan truck model will have diagrams and instructions on door panel removal. You can find these online (often as PDFs) or at auto parts stores.
Important Considerations:
* Patience: Take your time. Rushing can easily break clips or damage the panel.
* Plastic Trim Tools: Invest in a set of these; they're essential for interior trim removal.
* Photos: Before you start, take pictures. This helps you remember how things go back together.
* Safety First: Disconnect the negative battery terminal before starting any electrical work.
If you've followed these steps and are still stuck, providing the specific model of your 1991 Nissan pickup (e.g., D21 King Cab, Hardbody) will allow for more targeted assistance. A picture of the door handle and the area where the panel seems stuck would also be helpful.
