I tried all weekend to put the Delrin insert plates in but couldn't get past the 22mm nut. The 13mm nuts were not big problem. But the 22mm wouldn't budge even after spraying liquid wrench and WD40. I tried attaching a long pipe to increase the leverage. I tried hammering the long lever to loosen the nut. No dice.

I tried heating the nut with heat. Loosen it barely. Enough to rotate the bracket but not enough to turn the nut any more. Finally snapped the socket extension right off the the wrench.

Very frustrating. I know what to do but the nut won't budge.