Have u ever taken a door panel off? There are little round clips in the cardboard. I know that a cloth works to remove the window cranks (if manual). It is the kind of job you don't want to rush on. It takes a careful touch. But I think, since the main material in the panel is cardboard (or kinda particle board), you can easily mod it to work by carving the clips to fit into the right spot. I've never done it but I've read the 4runner doors are close to the same size. You might want to look into door swaps along with panels for more ideas.
If they are the same generation as what you are putting them in, it should work. Compare them to what you have. I've heard different things about 4runner doors so I can't verify what the differences in the door are. Measure for yourself. I do that a lot since I get tired of mixed info from the interwebs.
Were those answers not good enough? What did you expect, a step by step tutorial with pictures explaining every step. God. Sometimes its better to actually take things apart yourself then to search for the answers online.
I believe someone on TM has 4runner panels in their truck but can't remember who. What about finding door panels from an SR5 pickup? They should be the same. But don't quote me on that.
The doors are basically the same. And visually the same. They should go straight on. even if they dnt go right on you can just make new door panels and make the arm rest fit where u want it... Not tryin to knock the idea but why try to fit the 4Runner ones??