OEM quality with this simple installation. 100% legal, no worries.
Most owners manuals have a nice explanation on how to access the lamps to change. If it says "see dealer" in you manual, it means that getting to the lamp will be a bit more difficult. Usually doing a web search will tell you how difficult it will be for the DIY to change. In most cases the bulb switch is pretty standard with minimal tools.
https://www.youtube.com/watch?v=xxZwJ7_qkh8