24V off road lights

I am the proud new Papa of a new to me '99 Ram 2500 cumins turbo diesel. I got a pretty good deal on two LED off road lights......F F F FREE! LOL! Anyways, the only experiance I have working on vehicle is with 12V vehicle systems and accessories, the problem I am having is that my truck is a 24V system and the lights are 24V as well :4-dontknow:. I have been told that there is an inline step down somehwere after the alternator and that the 24V is to start the vehicle so I think I will be good on accessories after that i.e. radio/stereo system. I guess my question is how do I install these lights, would they go in before the alternator streight off the battery, and if so do i need to run a positive line from both batteries to the swtich and then one back out to the lights. And how is the ground gonna be done switch and lights, switch to lights then ground th lights? really lost on this, any help is appreciated.