My 1987 Ranger did not come with factory door speakers so I had to modify my door panels by making a custom speaker bracket. See the pictures below.
Stock door panel.
Remove door panel and mark the speaker cutout hole in an area that does not obstruct the window crank.
Cut-out speaker hole with jig saw.
Measure size of new speaker bracket and cutout speaker hole.
Drill holes on bracket in the areas that will have direct contact with the door surface.
Although the two pieces of sheet metal fit very tight, I added some silicone to avoid any possibility of speaker vibration.
Attach speaker bracket to door sheet metal using 1/8" rivets.
Use plenty of rivets for a solid fit.
Trace speaker hole onto door panel.
Cut out speaker hole using 4" hole saw.
Drill from the inside out for a clean cut.
Run speaker wire through rubber grommets on doors and insert screw clips.
Attach speaker grill and repeat the entire process for the other door.