How do I replace inside door handle

Hello, You may not be able to access the door handle mounting screws and cables without removing the entire door panel. You'll just have to check around the door for screws, screw covers, trim panels that pop off, and, once all that is out, use a plastic pry tool to pull the door panel away from the door frame. There are little clips that attach to the door panel and are pressed into the frame to hold the door panel on, they should come out with the door panel. Being 9-10 years old, some of those clips will break, so get some in advance if possible.