Know how vs know what

I have more common sense than knowledge. I've taken apart many machines without having taken classes or read user manuals, and figured out what their problems are. When it comes to defining my exact abilities, I look like a retard because I don't know any of the proper terminology for what I do.

"How did you fix your car stereo?"
"I saw that thing was black, so I pulled it out, took one out of another radio, and stuck it in."
"So you replaced the transistor?"
"Um... Sure."

Jam it back in, in the dark.