Well i want to replace the front 4x6" speakers, do i have to remove the entire door trim?

thanks!

Yes, unless yours has some sort of custom speaker covers. It never ceases to amaze me how resourceful people can get.

hehe, well it's difficult to get diagram and the stock grill makes me confused about how it made.

The stock door speaker grill covers the speaker but you cant remove the speaker without taking off the panel. It is pretty straightforward. There is one screw that holds the trim piece on the upper part of the door. There are two others under the door handle. (12 or 13mm) Remove the little sail panel at the top of the door that covers the little cable for the side view mirror. Lastly use a forked upholstery tool to pop the door pins and lift the door out about 6 inches and lift straight up and disconnect the switches for the window and door lock. Should take you 5-10 minutes.
Be careful of the mounting height of the new speaker as there is not much room behind the grille. I had a 6" in the door and they were making contact with the rear of the door panel. Putting a 10" in there now but that takes a great deal of modification