Its not difficult. I did a "Speedway Automotive" 20 circuit harness in mine. It is almost as good as a Painless with 1/3 the cost. All wires are labeled, color coded and comes with an easy to follow schematic. Makes for doing custom gauges/dash pretty easy. You can remove whatever wiring you don't need. I chose the 20 circuit for future expansion, but a 12 circuit will do you just fine. The harness includes everything for headlights, tail lights, blinkers, hazards, horn; all the basic requirements.
91 YJ, 350/700R4/231, 8.8/HPD30 with 3.73s, 6" SOA with 38" TSLs. If I ever see the previous owner again, I am going to curb stomp that meth-head brain dead crackpot.