not that hard, need a flathead screwdriver, some butyl tape, "chrome" spray paint and a little patience.
Pry the old lenses off the housing gently with the screwdriver, you might have to work your way around the lens a couple of times to work it loose.
After you get it off take the flathead and scrape all the old tape off of the housing, the new stuff wont seal with it on there. There are clips with little tabs on the housing, pry those tabs up a little so they will hold the lens on. Tabs hold it, tape seals it. It will make more sense when your looking at it.
clean the silver part of the housings and give them a coat of the chrome paint.
put the new butyl tape on the edge of the lens and press everything back together. easy peasy.