You can find a video on door panel removal by just typing it in on google, but basically, you remove the two access ports, screws, then control panel, hidden screw, door light, then ease the sail panel off.
The purpose for my reply is to mention a possible root cause for the inside handle not working when the outside does work. If the cable is working ok and the mechanism is not sticking, look behind the door handle by the spring. On mine, I found a piece of the plastic handle lodged in the way preventing the handle from pulling all the way open. Once removed, it works fine. We complained the day we bought it about the plastic handles. Now we have good reason.