Well that. I want to change the speakers and I don't see screws to remove the door panel !!! Are you going to pressure? .. Outside, up ... for some side? Where?.
The first thing is to disassemble the window of the windows, the handle to open the door from the inside and the door handle to close it from the inside.
The window of the windows is taken with a circlip and you will need a wire with a hook at the tip to get it out of its place and be able to disassemble it.
The other two pieces are screwed and the Vá panel caught with plastic staples that you have to take care of not breaking them.
Once this is done, strips of the panel up to trigger it from the upper part and you already have it disassembled.
Anyway, be the Opel Frontera manual or ask to see who has it because it is the same model as the Isuzu Rodeo and the Isuzu Amigo.
I finally disassembled it. They are just clips that go to pressure. You just have to disassemble the beautification of the door shooter and the electric panel of the windows and mirrors.
Now the problem is to find the support of the speakers. It is a piece of flange type plastic that is attached to the speaker !!!!. They are already worth.
I send the photo in case it knows where to find them.