I found some of the original sockets (glove box and switch lights?? if I recall) were reverse polarity, the pin was ground and the housing was positive. I took the LED bulbs and melted the metal on the pin with a soldering iron to separate the plastic LED from the metal bulb housing, switched the wires and re-soldered the bulb assembly. Not too difficult but took a bit of time and trial. These were the cheapest LED bulbs from ebay, not sure if you could do it to a better quality bulb.
You could have, as an alternative, cut the two wires to the socket and reversed them. If you soldered them and shrink wrapped them there would be nothing wrong with that. If, at some point, you wanted to go back to incandescent s (who would?) they would still work as they are not polarity dependent.