it depends on how old your car is, if it's newer i would have to say it's the total opposite of easy and simple, it's not easy and you will be lucky if you find a local shop to do it for less than $1000, it's very labour intensive. I've done around 40 sets of lights for the local G35 and 350z guys and other Nissan guys... these newer lights with silicone are hard to take apart and have more than 1 bezel piece inside which makes it difficult to pry apart.
but on the other hand I've done a few 300zx lights and instead of silicone they use butyl, which is a much much softer compound and quite a bit easier to take apart, so i would assume the shops who really know headlights wouldn't have a problem taking on projects like this with headlights who use GLASS for their bezel as opposed to plastic, it's very easy to melt the plastic bezel i learned the hard way myself, this is why shops won't do newer plastic bezel style lights. So my suggestion is if it's an older car DIY it for sure because like i said glass you can't melt in an oven, but if it's a newer car find someone local, and don't PM me I've stopped doing it a while ago, and i used to charge $250 for a set but it takes up too much of my time
here's some examples from the work i've done previously
older headlights with grey butyl
and some 350z lights with silicone and various bezel pieces that are super easy to snap when prying apart the lights