What I used to do at the dealership when a customer didn't want to spend the $$$ to replace a failed module, was unplug the lamp outage module inside the rear trim panel, (near the left rear tail light IIRC), then plug the harness back together. Doing this eliminates the light out warnings. I think there was an easy access panel there, just reach in and unplug it.

Installing the load resistors will cause the light circuits to draw as much current as the regular bulbs, eliminating one of the benefits of using LED's.

If you want to keep the lamp outage module in place, simply install the load resistors in parallel as seen in the second photo, one at each bulb. I don't see you needing 50 watt resistors on all the bulbs, most draw much less wattage, especially the third brake, license and side marker bulbs. Maybe 5 watts at most. You can google the bulb numbers and find the wattage ratings of each of them. Your local Radio Shack/Electronics parts store probably has them in stock.