Installing Arm Rests

We wanted armrests on the front seats of our new Promaster. I have a glitchy back, and I really like being able to support my back a bit on the armrests when driving. The driver seat has a right-side armrest, but the left side “armrest’ is built into the door and about a mile and a half away from my elbow. The passenger seat does not have any armrests at all.