I did mine according to the owners manual. It did take two tries. My tech said "DO NOT" cut or bypass wires under seat due to the passive airbag restraint system that they use in our new trucks!

 

I had done mine about 10 times with no luck until I read this thread. I had been latching / unlatching the buckle at least 4 times, based on what the owners manual said. That was while starting the truck. Last night, I simply turned the key to run (did not start the truck), unlatched / relatched exactly 3 times, and shut the truck off. DING. Worked first try.

Thanks for the tip, guys!