I just took my 89 father in law yesterday. Cherokee, so low wing. Got a step stool instead of the shin buster step. Had one of the line guys near the step, I stood on the wing. Got him in the seat by having him lean against the back and slide down. A bit tough getting the last foot in. Getting out was a challenge until we just said, let's slide down the walkway on your butt. Feet out, boost himself onto the wing walk, a couple scoots and onto the step stool. Relatively easy with two people. Just for context, he walks with a cane and is not what I would call steady on his feet.
Hardest part was me getting in over him. Flew to the Shuttle landing facility and did a low pass.
Think he enjoyed it. He bragged about it to my brother in law later. The only time he looked afraid was when I offered him the controls.