tail lights, too

Also, my tail lights don't work. Brake lights, turn signals work fine. I am trying to fix this myself. I bought a book but find no page on tail lights..and what are all those funny weird electrical diagrams?! Are we suppose to be able to understand all those squiggly lines? I want an easy fix. What if I just kick the tires or something, will that fix the tail lights and the heater? I see airplane pilots do it! Also, it is freezing cold here, can I fix these things from my living room (my fingers get cold easily)?

What year of Cherokee do you have?
Engine size (4 or 6 cyl?)

it is a 1987 and have no idea what size the emgine is....this luxury model is new to me, so I don't know it well yet....