If you can master a screwdriver, you can switch the lights. First of all....watch the wiring. It is always to short and you can loose the working end inside the wall. Thats a problem..
Go with newer LED fixtures. They come in the same Bullseye lens. You can always just change the bulbs to LED...a simple plug in swap.
EBAY, AMAZON, most anywhere.
Don't forget to seal them well.....everywhere. Those lights are the source of many water leak problems.
"If it can't be reduced, reused, repaired, rebuilt, refurbished, refinished, resold, recycled or composted
then it should be restricted, redesigned or removed from production."