Well, I have set-up over 7 pre-2006 Wranglers for flat towing.
No way would I ever consider bolting a tow bar to the factory front bumper either. (Lightweight metal) Not even if you reinforced it. I would only recommend a decent baseplate attached to the frame and a tow bar rated at 5,000 lbs.
Personally I would not go with diodes. Go with the BX 8869 kit... Use the Blue Ox "Bulb and Socket Tail Light Wiring Kit" with the part number "BX8869" when wiring your Wrangler. The kit is complete, easy to install and comes with excellent instructions. You can view the INSTRUCTIONS
here.
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By the way, when you remove the Wrangler tail light lenses you will see inside the tail light a removable, aluminum crosspiece which you will drill a 1" in diameter hole in to hold the 3 wire automotive socket that holds the bulb. Use some thought before drilling as you do not want the bulb to close to the tail light lenses, plastic tail light housing or the other bulb in the tail light housing.. There is room, just space all out so there are no heat issues. Best bet is to secure the 3 wire automotive socket with the fold over tabs but also with some GOOP brand flexible epoxy that you can buy at say Home Depot or Lowes. The adhesive will assure that the socket does not vibrate loose and do heat damage, etc.. Goop flexible epoxy is terrific as it withstands vibration when rock hard adhesives will vibrate loose. Once the 3 wire automotive socket is secured in the taillight you just feed out the 3 wires from it through the existing rubber tail light grommet. OH, there is a large hole with grommet on the drivers side firewall that you can fish the wires through. No firewall drilling necessary.
Anyway, the install is easy for most anyone and only simple hand tools and an electric drill with bits will be needed. Adding the bulb is better then using diodes which are very often problematic. I caution you do not try to jury rig a Walmart trailer harness instead of using the BX 8869 kit. Just makes for a jury rig, poorly grounded install..